JP2009016406A - Semiconductor having through conductor, and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a semiconductor having a through conductor and a manufacturing method thereof, which can be manufactured in a simple method (process) at a more reduced manufacturing cost. <P>SOLUTION: An SiO<SB>2</SB>film (first insulating film) 23 covers the internal flank of a through hole 14 of a silicon substrate 11 and the reverse surface of the silicon substrate 11 and has a perforated hole 31 reaching the reverse surface of a surface electrode 15 in the through hole 14. A wiring film 24 is formed in predetermined pattern on the SiO<SB>2</SB>film 23 and brought into contact with the reverse surface of the surface electrode 15 through the perforated hole 31 in the through hole 14. An external electrode 25 is formed on the wiring film 24 and has a filling portion 25a filling a cap left inside the wiring film 24 in the through hole 14, and the part of the wiring film 24 in the through hole 14 and the filling portion 25a function as the through conductor. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a semiconductor device and a manufacturing method thereof, and more specifically, a semiconductor device (for example, a solid-state imaging device) having a conductor extending through a semiconductor substrate in the thickness direction (hereinafter referred to as a through conductor). And a manufacturing method thereof.

  In recent years, solid-state imaging devices have been further miniaturized and enhanced in functionality, but along with this, they are increasingly being installed in portable devices such as mobile phones and portable computers, as well as automobiles, etc. It is spreading more and more.

  A solid-state imaging device is generally configured by sealing a chip-shaped solid-state imaging device in a synthetic resin package including a transparent cover (glass cover), and entering the solid-state imaging device through the transparent cover. Is irradiated to an imaging surface (light receiving surface) provided on the surface side of the solid-state imaging device. The output terminal of the solid-state imaging device is electrically connected to a plurality of external electrodes provided in the package, and an electrical signal generated by the solid-state imaging device according to incident light is transmitted through the external electrode. It is supplied to a circuit outside the solid-state imaging device. The package having such a configuration is called a chip-size package (CSP) because it has almost the same size as a chip-shaped solid-state imaging device.

  By the way, in this type of solid-state imaging device, when the external electrode is arranged on the back side of the solid-state imaging device (or package), a semiconductor substrate constituting the solid-state imaging device is used to reduce the size of the solid-state imaging device. In some cases, a conductor (penetrating conductor) extending in the thickness direction is used. This is because when the wiring that electrically connects the output terminal on the front surface side of the solid-state imaging device (the semiconductor substrate) and the external electrode on the back surface side is disposed outside the solid-state imaging device, This is because the size of the solid-state imaging device is increased accordingly, but if the through conductor is used, it is not necessary and the solid-state imaging device can be further downsized. The through conductor is also called a through electrode, a buried wiring, a conductive plug, or the like.

  An example of a solid-state imaging device having such a through conductor is disclosed in, for example, Non-Patent Document 1 (“Nikkei Electronics”, November 21, 2005, “Improving Value with Alternative Package Regardless of Wire Connection”, pages 105- 109). The solid-state imaging device described in FIG. 3 on page 108 of Non-Patent Document 1 (manufactured by Zycube Co., Ltd.) has a through conductor that penetrates the solid-state imaging device (bare chip) in its thickness direction. The electrodes (pads) on the front surface side of the solid-state image sensor are electrically connected to the wiring of the printed circuit board on the back surface side of the solid-state image sensor through these through conductors.

  A general method for forming such a through conductor is as follows. First, etching is performed from the back side of the semiconductor substrate to form a plurality of through holes that reach the pads (surface electrode or wiring film) on the front side of the semiconductor substrate. Next, after covering the inner side surfaces of these through holes with an insulating film and depositing a conductive material so as to fill the inside of these through holes, this is patterned and one end is brought into contact with the corresponding pad. A conductive plug (through conductor) is obtained. These conductive plugs are through conductors. Thereafter, a wiring film having a predetermined pattern is formed on the back side of the silicon substrate via an insulating film. These wiring films are in contact with the other ends of the corresponding conductive plugs. Finally, external electrodes are formed at desired positions on the wiring film. Thus, each of the external electrodes can be electrically connected to the corresponding pad (surface electrode or wiring film) via the wiring film and the conductive plug.

A known method for forming such a through conductor is disclosed in Patent Document 1. This describes a through electrode used in a semiconductor device having a three-dimensional stacked structure (see the fourth embodiment, FIGS. 17 to 20 and paragraphs 0182 to 0187).
"Nikkei Electronics" November 21, 2005 (pages 105-109) WO2006 / 0119156A1 (Fourth embodiment, FIGS. 17 to 20, paragraphs 0182 to 0187)

  However, in the above-described general method for forming the through conductor, the through hole is formed by etching the semiconductor substrate, the inner surface of the through hole is covered with the insulating film, the through hole is filled with the conductive material, and the conductive material is patterned. Many processes such as formation of conductive plugs (penetrating conductors), coating of an insulating film on the back surface of the semiconductor substrate, formation of a wiring film on the insulating film on the back surface of the semiconductor substrate, and formation of external electrodes on the wiring film Therefore, there is a problem that the manufacturing process is complicated and the manufacturing cost is high. Therefore, it is desired to reduce the manufacturing cost by allowing the through conductor and the external electrode to be formed with a fewer number of steps and a method (process) that is easy to implement.

  Thus, reducing the manufacturing cost is necessary not only for the solid-state imaging device but also for various semiconductor devices having penetrating conductors other than the solid-state imaging device.

  The present invention has been made in view of the above points, and the object of the present invention is to produce a method (process) that is simpler than the above-described general method for forming a through conductor and lower in production. An object of the present invention is to provide a semiconductor device capable of forming a through conductor at a low cost and a manufacturing method thereof.

  Another object of the present invention is to provide a semiconductor device capable of reducing the electrical resistance of a path including a through conductor and an external electrode, and a method for manufacturing the same.

  Other objects of the present invention which are not specified here will become apparent from the following description and the accompanying drawings.

(1) A semiconductor device according to a first aspect of the present invention includes:
A semiconductor device having a through conductor penetrating a semiconductor substrate,
A semiconductor substrate having a predetermined element or circuit formed on the front surface side and having a through hole penetrating from the front surface side to the back surface side;
A surface electrode electrically connected to the element or circuit, formed at a position overlapping the through hole on the surface side of the semiconductor substrate;
A first insulating film that covers the inner surface of the through hole and the back surface of the semiconductor substrate, and has a through hole that reaches the back surface of the front electrode inside the through hole;
A wiring film formed in a predetermined pattern on the first insulating film, and in contact with the back surface of the front surface electrode through the through hole in the through hole;
An external electrode formed on the wiring film, and the external electrode has a filling portion that fills a void remaining inside the wiring film inside the through hole,
A portion inside the through hole of the wiring film and the filling portion function as the through conductor.

  In the semiconductor device according to the first aspect of the present invention, the inner surface of the through hole of the semiconductor substrate and the back surface of the semiconductor substrate are covered with the first insulating film, but are formed on the first insulating film. The wiring film is brought into contact with the back surface of the front surface electrode through the through hole of the first insulating film inside the through hole. Further, the external electrode formed on the wiring film has the filling portion, and the filling portion fills the void remaining inside the wiring film inside the through hole. . The portion of the wiring film inside the through hole and the filling portion function as the through conductor. For this reason, after depositing a conductive material (polysilicon or the like) so as to fill the inside of the through hole, as in the above-described general method for forming a through conductor, the conductive material is patterned to form a conductive plug. A step of forming (penetrating conductor) is unnecessary.

  In addition, after forming the wiring film so as to contact the surface electrode through the through hole of the first insulating film inside the through hole, the external electrode is formed on the wiring film to form the gap. For example, the wiring film is made of metal, and the external electrode having the filling portion is formed by electroless plating of a metal having good conductivity using the wiring film as a seed metal. Can do. Therefore, the process of forming the external electrode is not only simplified compared to a method of depositing a conductive film using a CVD (Chemical Vapor Deposition) method or a PVD (Physical Vapor Deposition) method and then patterning the conductive film. The process itself can be carried out at a low cost.

  Therefore, a semiconductor device having a through conductor can be manufactured by a method (process) simpler than the above-described general method of forming a through conductor and at a lower manufacturing cost.

  Furthermore, in the semiconductor device according to the first aspect of the present invention, the wiring film is formed on the first insulating film, and the external electrode is formed on the wiring film. In addition, the wiring film is in contact with the back surface of the front surface electrode through the through hole of the first insulating film inside the through hole. For this reason, since only the wiring film exists between the surface electrode and the external electrode, there is no need to structurally interpose another conductive material such as polysilicon. Further, since a metal (for example, copper) having a low electric resistance can be used for the wiring film and the external electrode, it is easy to lower their electric resistance. Therefore, the electrical resistance of the path including the through conductor and the external electrode can be made lower than that using the general method for forming the through conductor described above.

  (2) In a preferred example of the semiconductor device according to the first aspect of the present invention, the first insulating film is formed directly on the inner surface of the through hole inside the through hole, and outside the through hole, A second insulating film is formed between the back surface of the semiconductor substrate and the first insulating film.

  In this example, since the first insulating film and the second insulating film exist between the back surface of the semiconductor substrate and the wiring film, electrical insulation between the back surface of the semiconductor substrate and the wiring film is good. As a result, there is an advantage that the first insulating film can be made thinner than the case where the second insulating film does not exist.

  (3) In another preferable example of the semiconductor device according to the first aspect of the present invention, the first insulating film is formed directly on the inner surface of the through hole inside the through hole, and the outside of the through hole. Then, the first insulating film is directly formed on the back surface of the semiconductor substrate.

  In this example, since the first insulating film is directly formed on the inner surface of the through hole and the back surface of the semiconductor substrate, there is an advantage that the formation of the first insulating film is simple. In this case, in order to ensure electrical insulation between the back surface of the semiconductor substrate and the wiring film, the thickness of the first insulating film is set to be larger or another insulating film is formed to overlap. preferable.

  (4) In still another preferred example of the semiconductor device according to the first aspect of the present invention, the through hole that covers the inner surface of the through hole and the back surface of the semiconductor substrate and reaches the back surface of the front electrode is formed in the through hole. A second insulating film provided inside the first insulating film is formed so as to overlap the first insulating film.

In this example, since the first insulating film and the second insulating film exist between the inner surface of the through hole and the wiring film and between the back surface of the semiconductor substrate and the wiring film, There is an advantage that the electrical insulation between the back surface and the wiring film becomes good. The first insulating film and the second insulating film may be made of the same material (for example, both are SiO ₂ ) or different materials (for example, one is SiO ₂ and the other is SiN _x ).

  (5) In still another preferred example of the semiconductor device according to the first aspect of the present invention, the through hole that covers the inner surface of the through hole and the back surface of the semiconductor substrate and reaches the back surface of the front electrode is formed in the through hole. A second insulating film is formed on the first insulating film so as to cover an inner surface of the through hole and the back surface of the semiconductor substrate, and a through hole reaching the back surface of the surface electrode. A third insulating film provided inside the through hole is formed so as to overlap the second insulating film.

  In this example, the first insulating film, the second insulating film, and the third insulating film exist between the inner surface of the through hole and the wiring film and between the back surface of the semiconductor substrate and the wiring film. Therefore, there is an advantage that the electrical insulation between the back surface of the semiconductor substrate and the wiring film becomes better. There is also an advantage that parasitic capacitance can be reduced by adjusting the types and thicknesses of the first insulating film, the second insulating film, and the third insulating film.

  (6) In still another preferred example of the semiconductor device according to the first aspect of the present invention, the external electrode is formed of a plated metal.

  In this example, there is an advantage that the external electrode having the filling portion can be easily formed at a low cost by using a plating method.

  (7) In still another preferred example of the semiconductor device according to the first aspect of the present invention, the thickness of the first insulating film on the inner surface of the through hole is the back surface of the semiconductor substrate of the first insulating film. It is set smaller than the upper thickness.

  In this example, after forming the first insulating film so as to cover the back surface of the front electrode, the inner surface of the through hole, and the back surface of the semiconductor substrate, it is anisotropically etched without a mask, Since the through hole can be formed by selectively removing only the portion of the first insulating film on the back surface of the front electrode, there is an advantage that the first insulating film can be easily formed. .

  (8) In still another preferred example of the semiconductor device according to the first aspect of the present invention, the semiconductor device is a solid-state imaging device.

(9) A method for manufacturing a semiconductor device according to a second aspect of the present invention includes:
A method for manufacturing a semiconductor device having a through conductor penetrating a semiconductor substrate,
A semiconductor substrate having a predetermined element or circuit formed on the surface side and a surface electrode electrically connected to the element or circuit on the surface side is prepared,
Selectively removing the semiconductor substrate from its back side, forming a through-hole that reaches the surface electrode through the semiconductor substrate from its back side to the front side;
Forming a first insulating film from the back surface side of the semiconductor substrate, covering the back surface of the semiconductor substrate, the inner surface of the through hole, and the back surface of the surface electrode;
By selectively removing a portion of the first insulating film on the back surface of the front surface electrode from the back surface side of the semiconductor substrate, a through hole reaching the back surface of the front surface electrode is formed in the first insulating film,
Forming a wiring film in a predetermined pattern on the first insulating film so as to contact the back surface of the front surface electrode through the through hole of the first insulating film inside the through hole;
Forming an external electrode on the surface of the wiring film so as to have a filling portion filling a void remaining inside the through hole;
A portion of the wiring film inside the through hole and the filling portion are made to function as the through conductor.

  In the method of manufacturing a semiconductor device according to the second aspect of the present invention, the through hole is formed in the semiconductor substrate from the back surface side, and then the first insulating film is formed from the back surface side of the semiconductor substrate. The back surface of the substrate, the inner surface of the through hole, and the back surface of the surface electrode are covered. Thereafter, by selectively removing a portion of the first insulating film on the back surface of the front surface electrode from the back surface side of the semiconductor substrate, a through hole reaching the back surface of the front surface electrode is formed in the first insulating film. Thus, the back surface of the front surface electrode is exposed. Then, the wiring film is formed in a predetermined pattern on the first insulating film so as to be in contact with the back surface of the front surface electrode through the through hole of the first insulating film inside the through hole. Finally, the external electrode is formed on the surface of the wiring film so as to have a filling portion that fills the void remaining inside the through hole.

  For this reason, when the external electrode is formed, the filling portion that fills the gap (this and the portion inside the through hole of the wiring film function as the through conductor) is formed together. The Therefore, after depositing a conductive material (polysilicon or the like) so as to fill the inside of the through hole, as in the general method for forming the through conductor described above, the conductive material is patterned to form a conductive plug ( The step of forming the through conductor) is not necessary.

  Further, after forming the wiring film so as to contact the back surface of the front surface electrode through the through hole inside the through hole, the external electrode is formed on the wiring film to fill the gap. Therefore, for example, the external electrode having the filling portion can be formed by producing the wiring film from a metal and using it as a seed metal by electroless plating of a metal having good conductivity. Therefore, compared to a method of depositing a conductive film using a CVD method or a PVD method and then patterning the conductive film, the process of forming the external electrode is simplified, and the process itself can be performed at a low cost. .

  Therefore, a semiconductor device having a through conductor can be manufactured by a method (process) simpler than the above-described general method of forming a through conductor and at a lower manufacturing cost.

  Furthermore, in the method for manufacturing a semiconductor device according to the second aspect of the present invention, the wiring film is formed in a predetermined pattern on the first insulating film, and the surface electrode is formed through the through hole in the through hole. Then, the external electrode is formed on the wiring film. For this reason, since only the wiring film exists between the surface electrode and the external electrode, a step of interposing another conductive material such as polysilicon is unnecessary. Further, since a metal (for example, copper) having a low electric resistance can be used for the wiring film and the external electrode, it is easy to lower their electric resistance. Therefore, the electrical resistance of the path including the through conductor and the external electrode can be made lower than that using the general method for forming the through conductor described above.

  (10) In a preferred example of the method for manufacturing a semiconductor device according to the second aspect of the present invention, the first insulating film is formed directly on the inner surface of the through hole inside the through hole, Outside, a second insulating film is formed between the back surface of the semiconductor substrate and the first insulating film.

  In this example, since the first insulating film and the second insulating film exist between the back surface of the semiconductor substrate and the wiring film, electrical insulation between the back surface of the semiconductor substrate and the wiring film is good. As a result, there is an advantage that the first insulating film can be made thinner than the case where the second insulating film does not exist.

  (11) In another preferable example of the method of manufacturing a semiconductor device according to the second aspect of the present invention, the first insulating film is formed directly on the inner surface of the through hole inside the through hole, and the through hole is formed. Outside the hole, the first insulating film is formed directly on the back surface of the semiconductor substrate.

  In this example, since the first insulating film is directly formed on the inner surface of the through hole and the back surface of the semiconductor substrate, there is an advantage that the formation of the first insulating film is simple. In this case, in order to ensure electrical insulation between the back surface of the semiconductor substrate and the wiring film, the thickness of the first insulating film is set to be larger or another insulating film is formed to overlap. preferable.

  (12) In still another preferred example of the method for manufacturing a semiconductor device according to the second aspect of the present invention, a through hole that covers the inner surface of the through hole and the back surface of the semiconductor substrate and reaches the back surface of the surface electrode is provided. A second insulating film provided inside the through hole is formed so as to overlap the first insulating film.

In this example, since the first insulating film and the second insulating film exist between the inner surface of the through hole and the wiring film and between the back surface of the semiconductor substrate and the wiring film, There is an advantage that the electrical insulation between the back surface and the wiring film becomes good. The first insulating film and the second insulating film may be made of the same material (for example, both are SiO ₂ ) or different materials (for example, one is SiO ₂ and the other is SiN _x ).

  (13) In still another preferred example of the method for manufacturing a semiconductor device according to the second aspect of the present invention, a through hole that covers the inner surface of the through hole and the back surface of the semiconductor substrate and reaches the back surface of the surface electrode is provided. A second insulating film provided inside the through hole is formed so as to overlap the first insulating film, covers the inner surface of the through hole and the back surface of the semiconductor substrate, and reaches the back surface of the surface electrode. A third insulating film having a through hole inside the through hole is formed so as to overlap the second insulating film.

  In this example, the first insulating film, the second insulating film, and the third insulating film exist between the inner surface of the through hole and the wiring film and between the back surface of the semiconductor substrate and the wiring film. Therefore, there is an advantage that the electrical insulation between the back surface of the semiconductor substrate and the wiring film becomes better. There is also an advantage that parasitic capacitance can be reduced by adjusting the types and thicknesses of the first insulating film, the second insulating film, and the third insulating film.

  (14) In still another preferred example of the method for manufacturing a semiconductor device according to the second aspect of the present invention, the external electrode is formed by a conductive metal plating method.

  In this example, there is an advantage that the external electrode having the filling portion can be easily formed at a low cost by using a plating method.

  (15) In still another preferred example of the method for manufacturing a semiconductor device according to the second aspect of the present invention, the first surface is covered so as to cover the back surface of the surface electrode, the inner surface of the through hole, and the back surface of the semiconductor substrate. After the insulating film is formed, it is anisotropically etched without a mask, and only the portion of the first insulating film on the back surface of the front surface electrode is selectively removed to form the through hole.

  This example has an advantage that the first insulating film can be easily formed.

  (16) In still another preferred example of the method for manufacturing a semiconductor device according to the second aspect of the present invention, the semiconductor device is a solid-state imaging device.

  In the semiconductor device according to the first aspect of the present invention and the method of manufacturing the semiconductor device according to the second aspect of the present invention, (a) a simpler method than that using the above-described general method for forming a through conductor ( (B) includes through conductors and external electrodes rather than using the above-described general method for forming through conductors. The effect that the electrical resistance of a path | route can be made lower than before is acquired.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described in detail with reference to the accompanying drawings.

(First embodiment)
FIG. 1 is a main part sectional view showing a schematic configuration of a solid-state imaging device 1 according to the first embodiment of the present invention, and FIG. 2 is a partially cutaway sectional view showing an entire configuration of the solid-state imaging device 1.

(Configuration of Solid-State Imaging Device of First Embodiment)
As shown in FIGS. 1 and 2, the solid-state imaging device 1 is configured by sealing a chip-shaped solid-state imaging element 10 in a chip size package (CSP). This package is formed of an insulating synthetic resin 50 that is opaque (that is, has a light shielding property) and a transparent glass cover 40. The insulating synthetic resin 50 covers only the side surfaces of the solid-state imaging device 10 and the glass cover 40. The glass cover 40 covers the upper surface of the solid-state image sensor 10, and the lower surface of the solid-state image sensor 10 is exposed.

  The solid-state imaging device 1 does not have a cavity between the imaging surface S on the surface of the solid-state imaging element 10 and the glass cover 40, but may have it. Further, the insulating synthetic resin 50 covering the side surfaces of the solid-state imaging device 10 and the glass cover 40 may be omitted when incident light from the side surfaces does not matter.

  The solid-state imaging device 10 includes a single crystal silicon (Si) substrate 11. A plurality of light receiving element regions 21 are formed in a predetermined layout on the surface of the silicon substrate 11, and a light receiving element (not shown) is formed in each of the light receiving element regions 21. The entire surface of the silicon substrate 11 is covered with a transparent interlayer insulating film 12, and a transparent interlayer insulating film 13 is formed on the interlayer insulating film 12.

  The surface of the interlayer insulating film 13 is the imaging surface S of the solid-state imaging device 10, and there are three colors for R (red), G (green), and B (blue) (add black to these three colors) The micro color filter 17 may be formed in an array. On the micro color filter 17, a plurality of microlenses 18a, that is, a microlens array 18, which are also arranged in an array, are formed. These microlenses 18 a are formed on the imaging surface S one by one for the R, G, and B color elements of the micro color filter 17. The elements of the microlens 18a and the microcolor filter 17 are arranged so as to overlap with the corresponding light receiving element regions 21 in the silicon substrate 11 through the interlayer insulating films 12 and 13, respectively.

  Three adjacent light receiving element regions 21 for three colors of R, G, and B, three elements of the micro color filter 17 and three micro lenses 18a overlapping with each other correspond to one pixel.

  The solid-state imaging device 10 defines a rectangular imaging region including the entire light receiving device region 21 on the imaging surface S, and senses light irradiated to the imaging region. Light (incident light) that has entered the solid-state imaging device 1 through the glass cover 40 from an external subject is irradiated on each of the light receiving element regions 21 via the microlens array 18 and the microcolor filter 17. Each light receiving element region 21 is converted into an electric signal corresponding to the received light intensity. These electric signals are subjected to predetermined signal processing by a signal processing circuit (not shown), and the image of the subject is reproduced. Thus, the subject is imaged.

  A plurality of surface electrodes 15 are formed on the surface of the interlayer insulating film 12 so as to surround the light receiving element region 21 in the outer peripheral region of the light receiving element region 21 (the peripheral region of the imaging region). These surface electrodes 15 are arranged at a predetermined interval over substantially the entire outer peripheral area of the rectangular ring shape. The surface electrode 15 is used for deriving an electric signal generated by the light receiving element in each light receiving element region 21 to the back side of the solid-state imaging element 10, and the surface of the silicon substrate 11 and the inside of the interlayer insulating film 12. Are electrically connected to the corresponding light receiving element regions 21 via lead-out wirings (not shown).

  The peripheral portion of each surface electrode 15 is covered with the interlayer insulating film 13, but the other portions are exposed from the interlayer insulating film 13. That is, in the rectangular ring-shaped region (surface electrode region) where the surface electrode 15 is disposed, a plurality of through holes that expose portions other than the peripheral portion of each surface electrode 15 are disposed at a predetermined interval. However, the entire surface of each surface electrode 15 may be covered with the interlayer insulating film 13.

  The surface of the interlayer insulating film 13 (that is, the imaging surface S) has irregularities due to the microlens 22, the micro color filter 17, and the surface electrode 15.

  There is no SOG material film on the surface of the interlayer insulating film 13 (imaging surface S), and a transparent adhesive film 30 is formed directly on the surface, covering the entire surface of the interlayer insulating film 13. Since the thickness of the adhesive film 30 based on the surface of the interlayer insulating film 13 (imaging surface S) is larger than the sum of the thickness (height) of the microlens 22 and the micro color filter 17, The micro color filter 17 is embedded in the adhesive film 30. Further, since the through holes formed in the interlayer insulating film 13 on each surface electrode 15 are also filled with the adhesive film 30, the surface electrode 15 is also embedded in the adhesive film 30. Therefore, the unevenness formed on the imaging surface S by the microlens 22, the micro color filter 17, and the surface electrode 15 is buried in the adhesive film 30, and the surface of the adhesive film 30 is flat.

The transparent glass cover 40 is placed on the flat surface of the adhesive film 30. In other words, the glass cover 40 is bonded to the surface (imaging surface S) of the interlayer insulating film 13 by the adhesive film 30 and is integrated with the chip-shaped solid-state imaging device 10. Here, the glass cover 40 is constituted by a cut piece of a transparent borosilicate glass (B ₂ O ₃ / SiO ₂ ) plate. However, it goes without saying that other glass and other transparent materials may be used.

  If necessary, an appropriate SOG material film may be disposed between the surface of the interlayer insulating film 13 (imaging surface S) and the adhesive film 30.

Immediately below each surface electrode 15, a through hole 12 a that penetrates the interlayer insulating film 12, a through hole 11 a that penetrates the silicon substrate 11, and a through hole 22 a that penetrates the silicon dioxide (SiO ₂ ) film 22 are mutually connected. It is formed to overlap. Here, the combination of the three through holes 12a, 11a, and 22a overlapped in this manner is referred to as a through hole 14 as a whole. That is, the through hole 14 is a hole that penetrates the solid-state imaging device 10 from the front surface side to the back surface side. Each through hole 14 (that is, the overlapping through holes 12 a, 11 a, and 22 a) is used to pull out each surface electrode 15 to the back surface of the solid-state imaging device 10.

The back surface of the silicon substrate 11 is covered with the SiO ₂ film 22 except for the opening of the through hole 14. The SiO ₂ film 22 does not extend into each through hole 14. That is, the SiO ₂ film 22 covers only the back surface of the silicon substrate 11.

On the SiO ₂ film 22, SiO ₂ film 23 is formed. The SiO ₂ film 23 extends not only to the back surface of the silicon substrate 11 but also to each through hole 14 and covers the inner side surface of each through hole 14.

On the back surface of the silicon substrate 11, a plurality of wiring films 24 patterned in a predetermined shape are formed directly on the SiO ₂ film 23. Each wiring film 24 is disposed in the vicinity of the corresponding through hole 14, and along the inner side surface of the through hole 14 (the surface exposed inside the through hole 14 of the SiO ₂ film 23). It extends (intrudes) and covers the entire inside surface. In addition, in the innermost part of the through hole 14, each wiring film 24 is in surface contact with the corresponding front surface electrode 15 (the back surface thereof), and covers the entire back surface of the front surface electrode 15 here. This is because the SiO ₂ film 23 does not exist in the innermost part of the through hole 14 and the corresponding front surface electrode 15 (the back surface thereof) is exposed.

The thickness of the SiO ₂ film 22 on the back surface of the silicon substrate 11 is set, for example, in the range of 0.3 μm to 4 μm. The same applies to the SiO ₂ film 23.

  On each wiring film 24, external electrodes 25 patterned directly into a predetermined shape are formed. Each external electrode 25 is located outside the corresponding through-hole 14 and the filling portion 25 a that fills the void 26 (see FIG. 13) remaining inside the corresponding wiring film 24 inside the corresponding through-hole 14. On the corresponding wiring film 24, an electrode portion 25b extending in a film shape is formed. Therefore, it can be said that each external electrode 25 is formed of an electrode portion 25b having a function as an electrode and a filling portion 25a having a function equivalent to that of a conductive plug. This is because the filling portion 25 a electrically connects the electrode portion 25 b and the surface electrode 15 through the wiring film 24.

  Each of the surface electrodes 15 on the front surface side of the silicon substrate 11 (solid-state image sensor 10) thus corresponds to the rear surface side of the silicon substrate 11 (solid-state image sensor 10) via the corresponding wiring film 24. The external electrode 25 is electrically connected. Therefore, the filling portion 25 a (and the wiring film 19) of the external electrode 25 inside the through hole 14 penetrates the silicon substrate 11 (solid-state imaging device 10) electrically through the surface electrode 15 and the external electrode 20. It can be said that it constitutes a “penetrating conductor” to be connected.

  The portion of each wiring film 19 that protrudes from the external electrode 25 is used as a wiring that connects desired external electrodes 25 on the back side of the silicon substrate 111. If such a wiring function is unnecessary, the pattern of each wiring film 19 and the pattern of the external electrode 20 may be the same.

As described above, in the solid-state imaging device 1 according to the first embodiment of the present invention, the through holes 11a, 12a, and 22a of the silicon substrate 11, the interlayer insulating film 12, and the SiO ₂ film 22 (this is equal to the through hole 14). ) Is covered with a SiO ₂ film 23 (first insulating film), and the back surface of the silicon substrate 11 except the opening on the back surface side of the silicon substrate 11 of the through hole 14 is covered with the SiO ₂ film 22 ( (Second insulating film). Further, the wiring film 24 brought into contact with the surface electrode 15 through the through hole 14 is formed on the SiO ₂ film 23, and the external electrode 25 having the filling portion 25 a filling the through hole 14 is formed on the wiring film 24. is doing. For this reason, a process of depositing a conductive material such as polysilicon thick enough to fill the inside of the through hole 14 and then selectively etching the conductive material to form a conductive plug is unnecessary.

Further, after forming the wiring film 24 so as to be in contact with the surface electrode 15 through the through hole 31 of the SiO ₂ film 23 inside the through hole 14, the external electrode 25 is formed on the wiring film 24 to form the void 26. Therefore, the external electrode 25 can be formed by an electroless plating method using the wiring film 24 made of metal as a seed metal. Therefore, as compared with a method of depositing a conductive film by using CVD or PVD and then patterning the conductive film, the process is not only greatly simplified, but those processes can be performed at low cost.

  Therefore, the solid-state imaging device 1 having a through conductor can be manufactured by a simpler method and at a lower manufacturing cost than those using the above-described general method for forming a through conductor.

  Furthermore, in the solid-state imaging device 1 according to the first embodiment of the present invention, the wiring film 24 is brought into contact with the back surface of the front electrode 15 and the external electrode 25 is formed on the wiring film 24. Only the wiring film 24 exists between the electrode 15 and the external electrode 25. For this reason, a conductive material such as polysilicon is unnecessary. Moreover, since a metal (for example, copper) with low electric resistance can be used for the wiring film 24 and the external electrode 25, those electric resistances can be lowered.

  Therefore, the electrical resistance of the electrical connection through the through conductor can be made lower than that of the conventional method using the general method for forming the through conductor.

(Method for Manufacturing Solid-State Imaging Device of First Embodiment)
Next, a manufacturing method of the solid-state imaging device 1 having the above configuration will be described with reference to FIGS.

  Each process of the manufacturing method described below is performed at the wafer level. In the final step of these steps (wafer process), as shown in FIG. 16, a plurality of imaging device sections 2 arranged in a matrix on the silicon wafer 11A are simultaneously formed. Each imaging device unit 2 is a region where the solid-state imaging device 1 having the above-described configuration is formed. After the imaging device unit 2 is formed, the silicon wafer 11A is diced along a plurality of scribe lines 53a and 53b set in a grid shape, and the imaging device units 2 are separated from each other. Thereafter, when the side surfaces of the solid-state imaging device 10 and the glass cover 40 are covered with the insulating synthetic resin 50, the solid-state imaging device 1 having the configuration shown in FIGS. 1 and 2 is manufactured.

  First, a plurality of solid-state imaging devices 10, that is, imaging device sections 2 having the configuration shown in FIG. 3 are formed in a predetermined layout on a silicon wafer 11A by a known method. These imaging device units 2 perform predetermined tests to confirm that they are non-defective products. In order to simplify the drawing, only the main part of one imaging device unit 2 is shown in FIG. 3, but actually, as shown in FIG. 16, a plurality of imaging device units 2 having the same configuration are arranged in a matrix. It is disposed on the wafer 11A.

  Next, as shown in FIG. 4, a coating film of an adhesive is formed on the surface of the silicon wafer 11A, more specifically, on the surface of the interlayer insulating film 13 (imaging surface S). This step is performed by applying a fluid adhesive in the atmosphere at room temperature by a spin coating method (or spray method). The surface of the adhesive coating becomes very flat.

  Next, as shown in FIG. 5, a wafer-like borosilicate glass plate 40A (which has the same shape and size as the silicon wafer 11A) is placed on the surface of the adhesive coating. Thereafter, when the coating film is cured by irradiating the coating film with ultraviolet rays having a predetermined wavelength at a predetermined intensity, the glass plate 40A is bonded to the surface of the silicon wafer 11A by the cured coating film (that is, the adhesive film 30).

  When the joining of the glass plate 40A forming the glass cover 40 is completed in this way, the laminated body composed of the silicon wafer 11A, the adhesive film 30, and the glass plate 40A is subsequently handled using an appropriate adhesive. Attach to a holder (not shown). The surface to which the adhesive is applied is the surface of the glass plate 40A. This is to facilitate the next processing (processing) of the silicon wafer 11A. The handling holder is slightly larger than the silicon wafer 11A.

  Then, in order to reduce the thickness of the entire silicon wafer 11A, the silicon wafer 11A is removed from the back side thereof until a predetermined thickness (for example, 100 μm to 50 μm) is reached. This step can be performed by CMP (Chemical Mechanical Polishing) or known dry or wet etching. A mechanical polishing method may be used in combination. The state at this time is as shown in FIG.

Next, as shown in FIG. 6, a SiO ₂ film 22 is formed by CVD on the back surface of the thinned silicon wafer 11A to cover the entire back surface of the silicon wafer 11A. The thickness of the SiO ₂ film 22 is preferably 0.2 μm to 3 μm, for example. A silicon nitride (SiN _x ) film can be used instead of the SiO ₂ film. Then, on the SiO ₂ film 22 to form a patterned resist film, the resist film as a mask 51 to selectively etch the SiO ₂ film 22. Since the mask 51 has the through holes 51A at the positions where the through holes 14 are to be formed, as shown in FIG. 7, the through holes 22a are formed in the SiO ₂ film 22 at the positions exposed from the through holes 51A. Is formed. Here, since isotropic wet etching using buffered hydrofluoric acid is used, the through hole 22 a is formed to be slightly larger than the through hole 51 A of the mask 51.

Subsequently, without removing the mask 51, the silicon wafer 11A is selectively etched from the back side thereof through the through hole 22a of the SiO ₂ film 22. Then, the through hole 11a is formed in the silicon wafer 11A at a position exposed from the through hole 22a. Further, without removing the mask 51, the silicon wafer 11A is selectively etched from the back surface side through the through holes 11a of the silicon wafer 11A. Then, a through hole 12a is formed in the interlayer insulating film 12 at a position exposed from the through hole 11a. Since the three through holes 22a, 11a, and 12a overlap each other, they form a single through hole 14 that penetrates the solid-state imaging device 10 as a whole. In this way, through holes 14 are formed at locations corresponding to the surface electrodes 15 of the solid-state imaging device 10. The state at this time is as shown in FIG.

  The positions where these through holes 14 are formed are directly below each surface electrode 15 (position overlapping each surface electrode 15). One end (the upper end in FIG. 8) on the front surface side of each through-hole 14 reaches the back surface of the corresponding front surface electrode 15. This step can be performed by dry etching such as RIE (Reactive Ion Etching) and ICE (Inductively Coupled Etching). However, it may be performed by a method such as laser processing or anodization.

When the mask 51 is peeled off, the state shown in FIG. 9 is obtained, and subsequently, the SiO ₂ film 23 is formed on the back surface of the silicon wafer 11A by the CVD method. At this time, the SiO ₂ film 23 is formed on the entire exposed surface inside the through hole 14 at the same time as the SiO ₂ film 23 is formed on the back surface of the silicon wafer 11A on the SiO ₂ film 22 formed on the back surface. As a result, as shown in FIG. 10, not only the surface of the SiO ₂ film 22 but also the inner surface of the through hole 14 and the back surface of the surface electrode 15 are formed.

The thickness of the SiO ₂ film 23 is preferably set in the range of 0.2 μm to 3 μm, for example. In this case, for example, if the thickness of the SiO ₂ film 23 on the surface of the SiO ₂ film 22 is 1 μm, the thickness on the inner surface of the through hole 14 is about 0.8 μm to about 1 μm, although it varies depending on the CVD conditions. Thus, the thickness of the back surface of the front electrode 15 is about 0.5 μm to about 0.6 μm.

Next, the SiO ₂ film 23 is anisotropically etched by RIE to selectively remove the portion of the SiO ₂ film 23 on the back surface of the front electrode 15 and expose the back surface of the front electrode 15. In this step, since no mask is used, a part of each part of the SiO ₂ film 23 on the surface of the SiO ₂ film 22 and the inner surface of the through hole 14 is removed, and the thickness of each part is reduced. For example, the thickness of the SiO ₂ film 23 decreases from 1 μm to about 0.5 μm on the surface of the SiO ₂ film 22 and decreases from 0.8 μm to about 0.6 μm on the inner surface of the through hole 14.

Between the rear surface of the SiO ₂ film 23 and the silicon wafer 11A, since the SiO ₂ film 22 is formed, SiO ₂ film 23 in the step of anisotropically etching the SiO ₂ film 23 on the surface of the SiO ₂ film 22 Even if this portion becomes too thin, the wiring film 24 does not contact the silicon wafer 11A and short-circuit.

Subsequently, after forming a metal film by sputtering, vapor deposition, metal CVD or the like, the metal film is patterned to form a wiring film patterned on the surface of the SiO ₂ film 23 as shown in FIG. A plurality of 24 are formed. Each of these wiring films 24 covers not only a predetermined portion of the back surface of the silicon wafer 11A but also the inside of the corresponding through hole 14 and the exposed back surface of the surface electrode 15. Inside each through hole 14, a void 26 is formed inside the wiring film 24.

  More specifically, for example, after forming a titanium (Ti) film as a barrier layer, a copper (Cu) film as a conductive material is formed thereon to obtain a Ti / Cu bilayer film. Thereafter, the desired wiring film 24 can be obtained by selectively etching the two-layer film using an appropriate mask. Instead of a Ti / Cu bilayer film, a TiW / Cu bilayer film, a Ti / TiN / TiCu trilayer film, a TaN / Cu bilayer film, a TaN / Al bilayer film, or the like is used. May be.

  Thereafter, a patterned resist film (for example, a photoresist film) is formed on the surface of each wiring film 24 by photolithography and etching to form a mask 52 as shown in FIG. Then, using the mask 52, a metal film is selectively formed on the surface of each wiring film 24 to form an external electrode 25 as shown in FIG.

  Specifically, for example, a Cu film is formed in the region surrounded by the mask 52 by the electroless plating method using the Cu film of the wiring film 24 as a seed metal to form the external electrode 25.

  As is clear from FIG. 14, each of the external electrodes 25 is inside the corresponding through hole 14 and has a filling portion 25 a that fills the gap 26 remaining inside the corresponding wiring film 24, and the corresponding through hole 14. And an electrode portion 25b extending in a film shape on the corresponding wiring film 24. Since the filling portion 25a has a function equivalent to that of the conductive plug, the conductive plug is formed together in the step of forming the external electrode 25. Therefore, the gap 26 is filled with a conductive material to be conductive. A process of forming a plug is not necessary.

  When the mask 52 is peeled after the formation of the external electrode 25, as shown in FIG. 15, the external electrode 25 is formed on the surface of each wiring film 24, and a plurality of imaging device sections 2 are completed on the silicon wafer 11A.

  When a plurality of imaging device sections 2 are formed on the silicon wafer 11A in this way, the silicon wafer 11A is formed along the scribe lines 53a and 53b (see FIG. 16) formed in a grid shape using a dicing blade. Dicing is performed. At that time, a known dicing tape (not shown) is attached in advance to the back surface of the silicon wafer 11A so that the imaging device unit 2 is not dispersed after cutting. By repeating this operation, the glass wafer 40A, the adhesive film 30, and the silicon wafer 11A on which the solid-state imaging device 10 is formed are cut along the scribe lines 53a and 53b. As a result, the imaging device units 2 on the silicon wafer 11A are separated from each other.

  A plurality of solid-state imaging devices 1 having the configuration shown in FIG. Therefore, when the entire side surface of each solid-state imaging device 1 is covered with the insulating synthetic resin 50, the solid-state imaging device 1 mounted on the CSP as shown in FIG. 2 is obtained. In addition, when it is not necessary to cover the whole side surface of the solid-state imaging device 1 with the insulating synthetic resin 50 that constitutes a part of the CSP, the manufacturing process ends when the imaging device unit 2 is separated from each other.

As described above, in the method of manufacturing the solid-state imaging device 1 according to the first embodiment of the present invention, the through holes 11a, 12a, and 22a of the silicon wafer 11A, the interlayer insulating film 12, and the SiO ₂ film 22 (this is the through hole). 14) is covered with the SiO ₂ film 23 (first insulating film), and the back surface of the silicon wafer 11A is removed from the SiO ₂ film except for the opening on the back surface side of the silicon wafer 11A of the through hole 14. 22 (second insulating film) is formed, and a wiring film 24 is formed on the SiO ₂ film 23 so as to be in contact with the surface electrode 15 through the through hole 14. Finally, the filling portion is filled with the through hole 14. An external electrode 25 having 25 a is formed on the wiring film 24. For this reason, a process of depositing a conductive material such as polysilicon thick enough to fill the inside of the through hole 14 and then selectively etching the conductive material to form a conductive plug is unnecessary.

  If the wiring film 24 is made of metal, it can be used as a seed metal to form the external electrode 25 by electroless plating. Therefore, as compared with a method of depositing a conductive film by using CVD or PVD and then patterning the conductive film, the process is not only greatly simplified, but those processes can be performed at low cost.

  Therefore, the solid-state imaging device 1 having a through conductor can be manufactured by a simpler method and at a lower manufacturing cost than those using the above-described general method for forming a through conductor.

  Further, since the wiring film 24 is brought into contact with the surface electrode 15 and the external electrode 25 is formed on the wiring film 24, only the wiring film 24 exists between the surface electrode 15 and the external electrode 25. It is. For this reason, a conductive material such as polysilicon is unnecessary. Moreover, since a metal (for example, copper) with low electric resistance can be used for the wiring film 24 and the external electrode 25, those electric resistances can be lowered.

  Therefore, it is possible to make the electrical resistance of the electrical connection through the through conductor lower than that using the general method for forming the through conductor described above.

(Configuration of Solid-State Imaging Device of Second Embodiment)
FIG. 17 is a cross-sectional view showing a schematic configuration of a solid-state imaging device 1A according to the second embodiment of the present invention.

In the solid-state imaging device 1A of the present embodiment, the back surface of the silicon substrate 11 and the inner surface of the through-hole 14 are covered with three insulating films of the SiO ₂ film 27, the SiN _x film 28, and the SiO ₂ film 29. And the first embodiment described above except that each wiring film 24 is in contact with the corresponding surface electrode 15 through the through hole 31 penetrating the three insulating films 27, 28 and 29. Since it has the same configuration as the solid-state imaging device 1, the same reference numerals are assigned to the same configuration parts as those of the solid-state imaging device 1 according to the first embodiment, and the description thereof is omitted.

  In the solid-state imaging device 1A according to the second embodiment of the present invention, the through-hole 12a that penetrates the interlayer insulating film 12 and the through-hole 11a that penetrates the silicon substrate 11 overlap each other immediately below each surface electrode 15. Is formed. In the second embodiment, the combination of the two through holes 12a and 11a thus overlapped is referred to as a through hole 14 as a whole. That is, the through hole 14 is a hole that penetrates the solid-state imaging device 10 from the front surface side to the back surface side. Each through-hole 14 (that is, the overlapping through-holes 12 a and 11 a) is used to pull out each surface electrode 15 to the back surface of the solid-state imaging device 10.

The back surface of the silicon substrate 11 is covered with the SiO ₂ film 27 except for the opening of the through hole 14, and the SiO ₂ film 27 extends into each through hole 14. The inner surface of each through-hole 14 and the back surface of each surface electrode 15 are covered.

On the SiO ₂ film 27, an SiN _x film 28 is formed so as to overlap. Similar to the SiO ₂ film 27, the SiN _x film 28 extends into each through hole 14, and not only the back surface of the silicon substrate 11 but also the inner surface of each through hole 14 and the back surface of each surface electrode 15. Is also covered.

An SiO ₂ film 29 is formed on the SiN _x film 28 so as to overlap therewith. Similar to the SiO ₂ film 27, the SiO ₂ film 29 extends into each through hole 14, and not only the back surface of the silicon substrate 11 but also the inner surface of each through hole 14 and the back surface of each surface electrode 15. Is also covered.

Thus, the back surface of the silicon substrate 11, the inner surface of each through-hole 14, and the back surface of each surface electrode 15 are covered with an insulating film having a three-layer structure including the SiO ₂ film 27, the SiN _x film 28 and the SiO ₂ film 29. This is different from the solid-state imaging device 1 according to the first embodiment described above.

The thickness of the SiO ₂ film 27 on the back surface of the silicon substrate 11 is set in the range of 0.3 μm to 4 μm, for example, as in the first embodiment. The thickness of the SiN _x film 28 on the back surface of the silicon substrate 11 is set, for example, in the range of 0.02 μm to 2.5 μm. The thickness of the SiO ₂ film 29 on the back surface of the silicon substrate 11 is the same as that of the SiO ₂ film 27.

On the back surface of the silicon substrate 11, a plurality of wiring films 24 patterned in a predetermined shape are formed on the SiO ₂ film 29. Each wiring film 24 is disposed in the vicinity of the corresponding through hole 14, and extends (enters) inside the through hole 14 to cover the entire inner surface. Further, in the innermost part of the through hole 14, each wiring film 24 has a corresponding surface electrode through a through hole 31 formed through the SiO ₂ film 27, the SiN _x film 28, and the SiO ₂ film 29. 15 (the back surface).

As described above, in the solid-state imaging device 1A according to the second embodiment of the present invention, the through holes 11a, 12a, and 22a of the silicon substrate 11, the interlayer insulating film 12, and the SiO ₂ film 22 (this is equal to the through hole 14). ) Is covered with a SiO ₂ film 23 (first insulating film), and the back surface of the silicon substrate 11 except for the opening on the back surface side of the silicon substrate 11 of the through hole 14 is the SiO ₂ film 22 ( (Second insulating film). Further, a wiring film 24 that is brought into contact with the surface electrode 15 through the through hole 14 is formed on the SiO ₂ film 23, and a filling portion 25 a that fills the through hole 14 is provided on the wiring film 24. An external electrode 25 is formed. For this reason, a process of depositing a conductive material such as polysilicon thick enough to fill the inside of the through hole 14 and then selectively etching the conductive material to form a conductive plug is unnecessary.

  If the wiring film 24 is made of metal, it can be used as a seed metal to form the external electrode 25 by electroless plating. Therefore, as compared with a method of depositing a conductive film by using CVD or PVD and then patterning the conductive film, the process is not only greatly simplified, but those processes can be performed at low cost.

  Therefore, the solid-state imaging device 1A having the through conductor can be manufactured by a simpler method and at a lower manufacturing cost than those using the above-described general method for forming the through conductor.

  Furthermore, in the solid-state imaging device 1A according to the second embodiment of the present invention, the wiring film 24 is brought into contact with the corresponding surface electrode 15 through the corresponding through hole 14, and the corresponding external electrode 25 is connected to the wiring. Since it is formed on the film 24, only the wiring film 24 exists between the surface electrode 15 and the external electrode 25. For this reason, a conductive material such as polysilicon is unnecessary. Moreover, since a metal (for example, copper) with low electric resistance can be used for the wiring film 24 and the external electrode 25, those electric resistances can be lowered.

  Therefore, it is possible to make the electrical resistance of the electrical connection through the through conductor lower than that using the general method for forming the through conductor described above.

(Method for Manufacturing Solid-State Imaging Device of Second Embodiment)
Next, a manufacturing method of the solid-state imaging device 1A having the above configuration will be described with reference to FIGS.

  Each process of the manufacturing method described below is performed at the wafer level as in the solid-state imaging device 1 according to the first embodiment, and a plurality of processes arranged in a matrix on the silicon wafer 11A in the final process. Are simultaneously formed. Thereafter, the silicon wafer 11A is diced along the scribe lines 53a and 53b to separate the imaging device sections 2 from each other, and then the side surfaces of the solid-state imaging device 10 and the glass cover 40 are covered with the insulating synthetic resin 50. A solid-state imaging device 1A having the configuration shown in FIG. 17 is obtained.

First, in the same manner as in the first embodiment, the silicon wafer 11A is removed from the back surface side to obtain a thinned configuration shown in FIG. Then, a patterned resist film is directly formed on the back surface of the silicon wafer 11A, and the silicon wafer 11A is selectively etched in the same manner as in the first embodiment using the resist film as a mask 54. Unlike the first embodiment, the SiO ₂ film 22 is not formed on the back surface of the silicon wafer 11A. Since each of the masks 54 has a through hole 54A at a position where the through hole 14 is to be formed, the through hole 11a is formed in the silicon wafer 11A at a position exposed from the through hole 54A as shown in FIG. It is formed. Here, since isotropic wet etching using buffered hydrofluoric acid is used, the through hole 22 a is formed to be slightly larger than the through hole 51 A of the mask 51.

  Further, similarly to the first embodiment, the interlayer insulating film 12 is selectively etched through the through hole 11a of the silicon wafer 11A without removing the mask 54. Then, a through hole 12a is formed in the interlayer insulating film 12 at a position exposed from the through hole 11a. Since the two through holes 11a and 12a overlap each other, they form a single through hole 14 that penetrates the solid-state imaging device 10 as a whole. In this way, through holes 14 are formed at locations corresponding to the surface electrodes 15 of the solid-state imaging device 10. The state at this time is as shown in FIG.

  The positions where these through holes 14 are formed are directly below each surface electrode 15 (position overlapping each surface electrode 15). One end (the upper end in FIG. 18) on the surface side of each through-hole 14 reaches the back surface of the corresponding surface electrode 15.

When the mask 54 is peeled off, the state shown in FIG. 19 is obtained. Subsequently, the SiO ₂ film 27 is formed by the CVD method. At this time, the SiO ₂ film 27 is formed on the entire back surface of the through hole 14 at the same time as being formed on the back surface of the silicon wafer 11A. As a result, as shown in FIG. 20, it is formed not only on the back surface of the silicon wafer 11A but also on the inner surface of the through hole 14 and the back surface of the surface electrode 15.

The thickness of the SiO ₂ film 27 is preferably set in the range of 0.2 μm to 3 μm, for example. In this case, for example, if the thickness of the SiO ₂ film 27 on the back surface of the silicon wafer 11A is 1 μm, the thickness on the inner surface of the through hole 14 is about 0.8 μm to about 1 μm, although it varies depending on the CVD conditions. The thickness of the back surface of the front electrode 15 is about 0.5 μm to about 0.6 μm.

Next, a SiN _x film 28 is formed on the SiO ₂ film 27 by a CVD method. As shown in FIG. 21, the SiN _x film 28 covers not only the back surface of the silicon wafer 11 _{</ b} > A but also the entire exposed surface inside the through hole 14.

The thickness of the SiN _x film 28 is preferably set in the range of 0.05 μm to 0.2 μm, for example. In this case, for example, when the thickness of the SiO ₂ film 27 on the back surface of the silicon wafer 11A is 0.1 μm, the thickness on the inner surface of the through hole 14 is about 0.08 μm to about The thickness of the front electrode 15 on the back surface is about 0.05 μm to about 0.06 μm.

Further, an SiO ₂ film 29 is formed on the SiN _x film 28 by a CVD method. As shown in FIG. 22, the SiO ₂ film 29 covers not only the back surface of the silicon wafer 11 </ _b > A but also the entire exposed surface inside the through hole 14.

The thickness of the SiO ₂ film 29 is preferably set in the range of 0.2 μm to 3 μm, for example. In this case, for example, if the thickness of the SiO ₂ film 29 on the back surface of the silicon wafer 11A is 1 μm, the thickness on the inner surface of the through hole 14 is about 0.8 μm to about 1 μm, although it varies depending on the CVD conditions. The thickness of the back surface of the front electrode 15 is about 0.5 μm to about 0.6 μm.

Next, the SiO ₂ film 29, the SiN _x film 28, and the SiO ₂ film 27 thus laminated are anisotropically etched by the RIE method, and the portions of these three films 29, 28, and 27 on the back surface of the surface electrode 15 are formed. Are selectively removed to form the through holes 31. At this time, as shown in FIG. 23, the back surface of the front electrode 15 is exposed through the through hole 31. In this step, since no mask is used, a part of the SiO ₂ film 29 is etched to reduce the thickness. For example, the thickness of the SiO ₂ film 29 decreases from 1 μm to about 0.5 μm on the back surface of the silicon wafer 11A, and decreases from 0.8 μm to about 0.6 μm on the inner surface of the through hole 14.

Since the SiN _x film 28 and the SiO ₂ film 27 are formed between the SiO ₂ film 27 and the back surface of the silicon wafer 11A, the SiO ₂ film 29 on the silicon wafer 11A is anisotropically etched. _{Even if the two} films 29 become too thin, the wiring film 24 does not contact the silicon wafer 11A and short-circuit.

In the solid-state imaging device 1A according to the second embodiment, unlike the first embodiment, the back surface of the silicon substrate 11, the inner surface of each through-hole 14, and the back surface of each surface electrode 15 are composed of the SiO ₂ film 27 and the SiN _x film. Since it is covered with an insulating film having a three-layer structure made up of 28 and SiO ₂ film 29, defects such as pinholes and film thickness variations can be easily corrected, and withstand voltage and moisture resistance are improved as compared with the first embodiment. As a result, there is an advantage that reliability is improved.

Subsequently, by forming a metal film by the same method as in the first embodiment and then patterning the metal film, the wiring film 24 patterned as shown in FIG. 24 on the surface of the SiO ₂ film 23. A plurality of are formed. Each of these wiring films 24 covers not only a predetermined portion of the back surface of the silicon wafer 11A but also the inside of the corresponding through hole 14 and the exposed back surface of the surface electrode 15. Inside each through hole 14, a void 26 is formed inside the wiring film 24.

  More specifically, for example, after forming a titanium (Ti) film as a barrier layer, a copper (Cu) film as a conductive material is formed thereon to obtain a Ti / Cu bilayer film. Thereafter, the desired wiring film 24 can be obtained by selectively etching the two-layer film using an appropriate mask. Instead of a Ti / Cu bilayer film, a TiW / Cu bilayer film, a Ti / TiN / TiCu trilayer film, a TaN / Cu bilayer film, a TaN / Al bilayer film, or the like is used. May be. This is the same as in the first embodiment.

  Thereafter, a patterned resist film (for example, a photoresist film) is formed on the surface of each wiring film 24 by photolithography and etching to form a mask 55 as shown in FIG. Then, using the mask 55, a metal film is selectively formed on the surface of each wiring film 24 to obtain an external electrode 25 as shown in FIG.

  Specifically, for example, a Cu film is formed in the region surrounded by the mask 52 by the electroless plating method using the Cu film of the wiring film 24 as a seed metal to form the external electrode 25.

  As apparent from FIG. 25, each of the external electrodes 25 is inside the corresponding through-hole 14 and fills the gap 26 remaining inside the corresponding wiring film 24 and the corresponding through-hole 14. And an electrode portion 25b extending in a film shape on the corresponding wiring film 24. Since the filling portion 25a has a function equivalent to that of the conductive plug, the conductive plug is formed together in the step of forming the external electrode 25. Therefore, the gap 26 is filled with a conductive material to be conductive. A step of forming a plug is not necessary.

  When the mask 52 is peeled after the formation of the external electrode 25, the external electrode 25 is formed on the surface of each wiring film 24 as shown in FIG. 26, and a plurality of imaging device sections 2 are completed on the silicon wafer 11A.

  When a plurality of imaging device sections 2 are formed on the silicon wafer 11A in this way, the glass plate 40A, the adhesive film 30, and the solid-state imaging device 10 are formed inside as in the first embodiment. The silicon wafer 11A is cut along the scribe lines 53a and 53b, and the imaging device unit 2 is separated from each other. Therefore, when the entire side surface of each solid-state imaging device 1 is covered with the insulating synthetic resin 50, the solid-state imaging device 1 mounted on the CSP as shown in FIG. 2 is obtained. In addition, when it is not necessary to cover the whole side surface of the solid-state imaging device 1 with the insulating synthetic resin 50 that constitutes a part of the CSP, the manufacturing process ends when the imaging device unit 2 is separated from each other.

As described above, in the method for manufacturing the solid-state imaging device 1A according to the second embodiment of the present invention, the plurality of through holes 14 are formed from the back surface side in a predetermined portion of the silicon wafer 11A, and then the back surface of the silicon wafer 11A. The SiO ₂ film 27 (first insulating film), the SiN _x film 28 (second insulating film), and the SiO ₂ film 29 (third insulating film) are stacked in this order from the side, and the back surface of the silicon wafer 11A and each through-hole are formed. The inner surface of the hole 14 and the back surface of each surface electrode 15 are covered. Thereafter, by selectively removing portions of the SiO ₂ film 27, the SiN _x film 28, and the SiO ₂ film 29 on the back surface of each front surface electrode 15, through-holes passing through the three films 27, 28, and 29 are obtained. 31 is formed inside each through-hole 14, and the back surface of each front surface electrode 15 is exposed. Then, a plurality of wiring films 24 are formed at predetermined positions on the SiO ₂ film 29 so as to be in contact with the back surface of each front surface electrode 15 through the corresponding through hole 30. Finally, a plurality of external electrodes 25 are formed on the wiring film 24 at predetermined positions so as to have a filling portion 25 a that fills the void 26 remaining inside the wiring film 24 inside each through hole 14.

  For this reason, when the external electrode 25 is formed, a filling portion 25a (which functions as a through conductor) that fills the gap 26 is formed together. Therefore, there is no need for a step of depositing a conductive material such as polysilicon thick enough to fill the gap 26 and then selectively etching the conductive material to form a conductive plug.

  If the wiring film 24 is made of metal, it can be used as a seed metal to form the external electrode 25 by electroless plating. Therefore, as compared with a method of depositing a conductive film by using CVD or PVD and then patterning the conductive film, the process is not only greatly simplified, but those processes can be performed at low cost.

  Therefore, the solid-state imaging device 1A having the through conductor can be manufactured by a simpler method and at a lower manufacturing cost than those using the above-described general method for forming the through conductor.

  Furthermore, in the method for manufacturing the solid-state imaging device 1 according to the second embodiment of the present invention, each wiring film 24 is formed in contact with the corresponding surface electrode 15 inside the corresponding through hole 14, and the wiring film Since the corresponding external electrode 25 is formed on 24, only the wiring film 24 exists between the surface electrode 15 and the external electrode 25. For this reason, a conductive material such as polysilicon is unnecessary. Moreover, since a metal (for example, copper) with low electric resistance can be used for the wiring film 24 and the external electrode 25, those electric resistances can be lowered.

  Therefore, it is possible to make the electrical resistance of the electrical connection through the through conductor lower than that using the general method for forming the through conductor described above.

(Configuration of Solid-State Imaging Device of Third Embodiment)
FIG. 27 is a cross-sectional view showing a schematic configuration of a solid-state imaging device 1B according to the third embodiment of the present invention.

In the solid-state imaging device 1B of the present embodiment, the back surface of the silicon substrate 11 and the inner side surface of the through hole 14 are covered with two insulating films of the SiO ₂ film 27 and the SiN _x film 28, and each wiring film The first embodiment described above, except that 24 is in contact with the corresponding surface electrode 15 through the through hole 31 passing through the two insulating films 27 and 28 inside the corresponding through hole 14. Since the configuration is the same as that of the solid-state imaging device 1 according to the embodiment, the same components as those of the solid-state imaging device 1 according to the first embodiment are denoted by the same reference numerals and description thereof is omitted.

  In the solid-state imaging device 1B according to the third embodiment of the present invention, the through hole 12a that penetrates the interlayer insulating film 12 and the through hole 11a that penetrates the silicon substrate 11 overlap each other immediately below each surface electrode 15. Is formed. In the third embodiment, as in the second embodiment, the combination of the two through holes 12a and 11a thus overlapped is referred to as a through hole 14 as a whole. That is, the through hole 14 is a hole that penetrates the solid-state imaging device 10 from the front surface side to the back surface side. Each through-hole 14 (that is, the overlapping through-holes 12 a and 11 a) is used to pull out each surface electrode 15 to the back surface of the solid-state imaging device 10.

The back surface of the silicon substrate 11 is covered with the SiO ₂ film 27 except for the opening of the through hole 14, and the SiO ₂ film 27 extends into each through hole 14. The inner surface of each through-hole 14 and the back surface of each surface electrode 15 are covered.

On the SiO ₂ film 27, an SiN _x film 28 is formed so as to overlap. Similar to the SiO ₂ film 27, the SiN _x film 28 extends into each through hole 14, and not only the back surface of the silicon substrate 11 but also the inner surface of each through hole 14 and the back surface of each surface electrode 15. Is also covered.

As described above, the back surface of the silicon substrate 11, the inner surface of each through-hole 14, and the back surface of each surface electrode 15 are covered with the two-layered insulating film composed of the SiO ₂ film 27 and the SiN _x film 28. The solid-state imaging device 1 according to the first embodiment and the solid-state imaging device 1A according to the second embodiment described above are different.

The thickness of the SiO ₂ film 27 on the back surface of the silicon substrate 11 is set in the range of 0.3 μm to 4 μm, for example, as in the first embodiment. The thickness of the SiN _x film 28 on the back surface of the silicon substrate 11 is set in a range of 0.02 μm to 2.5 μm, for example, as in the second embodiment.

On the back surface of the silicon substrate 11, a plurality of wiring films 24 patterned in a predetermined shape are formed on the SiN _x film 28. Each wiring film 24 is disposed in the vicinity of the corresponding through hole 14, extends (enters) along the inner side surface of the through hole 14, and covers the entire inner side surface. Yes. Further, in the innermost part of the through hole 14, each wiring film 24 has a corresponding surface electrode 15 (the back surface thereof) through a through hole 31 formed through the SiO ₂ film 27 and the SiN _x film 28. Is in surface contact.

As described above, in the solid-state imaging device 1B according to the third embodiment of the present invention, the SiO ₂ film 27 (first insulating film) and the SiN _x film 28 are formed on the back surface of the silicon substrate 11 and the inner surface of the through hole 14. After covering with the (second insulating film), the wiring film 24 brought into contact with the surface electrode 15 is formed on the SiN _x film 28. Finally, the external electrode 25 having the filling portion 25a filling the gap 26 is wired. It is formed on the film 24. For this reason, a process of depositing a conductive material such as polysilicon thick enough to fill the inside of the through hole 14 and then selectively etching the conductive material to form a conductive plug is unnecessary.

  If the wiring film 24 is made of metal, it can be used as a seed metal to form the external electrode 25 by electroless plating. Therefore, as compared with a method of depositing a conductive film by using CVD or PVD and then patterning the conductive film, the process is not only greatly simplified, but those processes can be performed at low cost.

  Therefore, the solid-state imaging device 1B having the through conductor can be manufactured by a simpler method and at a lower manufacturing cost than those using the general method for forming the through conductor described above.

  Further, since the wiring film 24 is brought into contact with the corresponding surface electrode 15 through the corresponding through hole 14 and the corresponding external electrode 25 is formed on the wiring film 24, the surface electrode 15 and the external electrode Only the wiring film 24 exists between the electrodes 25. For this reason, a conductive material such as polysilicon is unnecessary. Moreover, since a metal (for example, copper) with low electric resistance can be used for the wiring film 24 and the external electrode 25, those electric resistances can be lowered.

  Therefore, it is possible to make the electrical resistance of the electrical connection through the through conductor lower than that using the general method for forming the through conductor described above.

(Method for Manufacturing Solid-State Imaging Device of Third Embodiment)
Next, a manufacturing method of the solid-state imaging device 1B having the above configuration will be described with reference to FIGS.

  Each process of the manufacturing method described below is performed at the wafer level as in the solid-state imaging device 1 according to the first embodiment, and a plurality of processes arranged in a matrix on the silicon wafer 11A in the final process. Are simultaneously formed. Thereafter, dicing is performed to separate the imaging device sections 2 from each other, and then the side surfaces of the solid-state imaging device 10 and the glass cover 40 are covered with an insulating synthetic resin 50, whereby the solid-state imaging device 1B having the configuration shown in FIG. can get.

First, in the same manner as in the second embodiment, the silicon wafer 11A is removed from the back surface side and thinned, and then the configuration of FIG. 19 in which the through holes 14 are formed is obtained. Then, the SiO ₂ film 27 is formed on the back surface of the silicon wafer 11A by the CVD method as in the second embodiment. At this time, the SiO ₂ film 27 is formed on the entire back surface of the through hole 14 at the same time as being formed on the back surface of the silicon wafer 11A. As a result, as shown in FIG. 28, it is formed not only on the back surface of the silicon wafer 11A but also on the inner surface of the through hole 14 and the back surface of the surface electrode 15.

The thickness of the SiO ₂ film 27 is preferably set in the range of 0.2 μm to 3 μm, for example. In this case, for example, if the thickness of the SiO ₂ film 27 on the back surface of the silicon wafer 11A is 1 μm, the thickness on the inner surface of the through hole 14 is about 0.8 μm to about 1 μm, although it varies depending on the CVD conditions. The thickness of the back surface of the front electrode 15 is about 0.5 μm to about 0.6 μm.

Thereafter, an SiN _x film 28 is formed on the SiO ₂ film 27 by the CVD method in the same manner as in the second embodiment. As shown in FIG. 28, the SiN _x film 28 covers not only the back surface of the silicon wafer 11A but also the inner surface of the through hole 14 and the back surface of the surface electrode 15.

The thickness of the SiN _x film 28 is slightly larger than that in the second embodiment, and is preferably set in the range of 0.1 μm to 1.5 μm, for example. In this case, for example, if the thickness of the SiN _x film 28 on the back surface of the silicon wafer 11A is 1 μm, the thickness on the inner surface of the through hole 14 is about 0.8 μm to about 1 μm, although it depends on the CVD conditions. The thickness of the back surface of the front electrode 15 is about 0.5 μm to about 0.6 μm.

Next, the SiO ₂ film 29 and the SiN _x film 28 thus laminated are anisotropically etched by the RIE method in the same manner as in the second embodiment, so that the back surfaces of the surface electrodes 15 of these two films 29 and 28 are formed. A portion is selectively removed to form a through hole 31 that penetrates the membranes 29 and 28. At this time, as shown in FIG. 29, the back surface of the front electrode 15 is exposed through the through hole 31. In this step, since no mask is used, the SiN _x film 28 is partially etched to reduce its thickness. For example, the thickness of the SiN _x film 28 decreases from 1 μm to about 0.5 μm on the back surface of the silicon wafer 11A, and decreases from 0.8 μm to about 0.6 μm on the inner surface of the through hole 14.

Between the back surface of the SiN _x film 28 and the silicon wafer 11A, since the SiO ₂ film 27 is formed, becomes thin the SiN _x film 28 the SiN _x film 28 on the silicon wafer 11A in the step of anisotropically etching the Even if it passes, the wiring film 24 does not contact the silicon wafer 11A and short-circuit.

In the solid-state imaging device 1B according to the third embodiment, unlike the first embodiment, the back surface of the silicon substrate 11, the inner surface of each through-hole 14, and the back surface of each surface electrode 15 are composed of the SiO ₂ film 27 and the SiN _x film. Since it is covered with an insulating film having a two-layer structure composed of 28, there are advantages that defects such as pinholes and film thickness variations can be easily corrected and the withstand voltage is improved as compared with the first embodiment. Further, since the SiN _x film 28 has a high barrier property against metal atoms (that is, the metal atoms in the adjacent metal film are difficult to diffuse into the SiN _x film 28), defects due to the diffusion of metal atoms are prevented, As a result, there is an advantage that reliability is improved.

Subsequently, a plurality of wiring films 24 patterned as shown in FIG. 30 are formed on the surface of the SiO ₂ film 23 by the same method as in the first embodiment. Each of these wiring films 24 covers not only a predetermined portion of the back surface of the silicon wafer 11A but also the inside of the corresponding through hole 14 and the exposed back surface of the surface electrode 15. Inside each through hole 14, a void 26 is formed inside the wiring film 24.

  Thereafter, a mask 55 shown in FIG. 31 is formed on the surface of each wiring film 24 by photolithography and etching, and the mask 55 is used to, for example, electroless the Cu film of the wiring film 24 as a seed metal. A Cu film is formed in the region surrounded by the mask 52 by plating to form the external electrode 25.

  As is clear from FIG. 31, each of the external electrodes 25 is inside the corresponding through hole 14 and fills the gap 26 remaining inside the corresponding wiring film 24 and the corresponding through hole 14. And an electrode portion 25b extending in a film shape on the corresponding wiring film 24. Since the filling portion 25a has a function equivalent to that of the conductive plug (penetrating conductor, through electrode), the conductive plug is formed together in the step of forming the external electrode 25. A step of filling with a conductive material to form a conductive plug is unnecessary.

  When the mask 52 is peeled after the formation of the external electrode 25, as shown in FIG. 32, the external electrode 25 is formed on the surface of each wiring film 24, and a plurality of imaging device sections 2 are completed on the silicon wafer 11A.

  When a plurality of imaging device units 2 are formed on the silicon wafer 11A in this way, the imaging device units 2 are separated from each other in the same manner as in the first embodiment. Therefore, when the entire side surface of each solid-state imaging device 1 is covered with the insulating synthetic resin 50, the solid-state imaging device 1 mounted on the CSP as shown in FIG. 2 is obtained. In addition, when it is not necessary to cover the whole side surface of the solid-state imaging device 1 with the insulating synthetic resin 50 that constitutes a part of the CSP, the manufacturing process ends when the imaging device unit 2 is separated from each other.

As described above, in the method for manufacturing the solid-state imaging device 1B according to the third embodiment of the present invention, after the plurality of through holes 14 are formed from the back surface side in a predetermined portion of the silicon wafer 11A, the back surface of the silicon wafer 11A is formed. The SiO ₂ film 27 (first insulating film) and the SiN _x film 28 (second insulating film) are laminated in this order from the side, and the back surface of the silicon wafer 11A, the inner surface of each through hole 14, and the back surface of each surface electrode 15 And covering. Thereafter, by selectively removing portions of the SiO ₂ film 27 and the SiN _x film 28 on the back surface of each front surface electrode 15, the through holes 31 penetrating the two films 27 and 28 are formed in each through hole 14. It is formed inside and the back surface of each surface electrode 15 is exposed. Then, a plurality of wiring films 24 are formed at predetermined positions on the SiN _x film 28 so as to be in contact with the back surface of each front surface electrode 15 through the corresponding through hole 31. Finally, a plurality of external electrodes 25 are formed on the wiring film 24 at predetermined positions so as to have a filling portion 25 a that fills the void 26 remaining inside the wiring film 24 inside each through hole 14.

  For this reason, when the external electrode 25 is formed, a filling portion 25a (which functions as a through conductor) that fills the gap 26 is formed together. Therefore, there is no need for a step of depositing a conductive material such as polysilicon thick enough to fill the gap 26 and then selectively etching the conductive material to form a conductive plug.

  If the wiring film 24 is made of metal, it can be used as a seed metal to form the external electrode 25 by electroless plating. Therefore, as compared with a method of depositing a conductive film by using CVD or PVD and then patterning the conductive film, the process is not only greatly simplified, but those processes can be performed at low cost.

  Therefore, the solid-state imaging device 1B having the through conductor can be manufactured by a simpler method and at a lower manufacturing cost than those using the general method for forming the through conductor described above.

  Furthermore, in the method of manufacturing the solid-state imaging device 1B according to the third embodiment of the present invention, each wiring film 24 is formed in contact with the corresponding surface electrode 15 inside the corresponding through hole 14, and the wiring film Since the corresponding external electrode 25 is formed on 24, only the wiring film 24 exists between the surface electrode 15 and the external electrode 25. For this reason, a conductive material such as polysilicon is unnecessary. Moreover, since a metal (for example, copper) with low electric resistance can be used for the wiring film 24 and the external electrode 25, those electric resistances can be lowered.

  Therefore, it is possible to make the electrical resistance of the electrical connection through the through conductor lower than that using the general method for forming the through conductor described above.

(Other embodiments)
The first to third embodiments described above show examples embodying the present invention. Therefore, the present invention is not limited to these embodiments, and it goes without saying that various modifications can be made without departing from the spirit of the present invention.

  For example, although the first to third embodiments have been described as the solid-state imaging device, the present invention is not limited to the solid-state imaging device. The present invention can also be applied to various semiconductor devices other than solid-state image sensors. The various processes such as CVD, plating, and etching used in the first to third embodiments described above are not limited to these processes, and other processes can be used as necessary.

  In the first to third embodiments described above, the solid-state imaging device has a microlens array and a microcolor filter, but these may be omitted. If necessary, a conductive member such as a solder ball (not shown) may be additionally formed on each external electrode.

It is principal part sectional drawing which shows schematic structure of the solid-state imaging device which concerns on 1st Embodiment of this invention. 1 is a partially cutaway cross-sectional view illustrating an overall configuration of a solid-state imaging device according to a first embodiment of the present invention. It is a fragmentary sectional view which shows the manufacturing method of the solid-state imaging device which concerns on 1st Embodiment of this invention for every process. FIG. 4 is a partial cross-sectional view illustrating the method for manufacturing the solid-state imaging device according to the first embodiment of the present invention for each step, and is a continuation of FIG. 3. FIG. 5 is a partial cross-sectional view illustrating the method for manufacturing the solid-state imaging device according to the first embodiment of the present invention for each process, and is a continuation of FIG. 4. FIG. 6 is a partial cross-sectional view illustrating the method for manufacturing the solid-state imaging device according to the first embodiment of the present invention for each process, and is a continuation of FIG. 5. FIG. 7 is a partial cross-sectional view illustrating the method for manufacturing the solid-state imaging device according to the first embodiment of the present invention for each process, and is a continuation of FIG. 6. FIG. 10 is a partial cross-sectional view illustrating the method for manufacturing the solid-state imaging device according to the first embodiment of the present invention for each step, and is a continuation of FIG. 7. FIG. 9 is a partial cross-sectional view illustrating the method for manufacturing the solid-state imaging device according to the first embodiment of the present invention for each process, and is a continuation of FIG. 8. FIG. 10 is a partial cross-sectional view illustrating the method for manufacturing the solid-state imaging device according to the first embodiment of the present invention for each step, and is a continuation of FIG. 9. FIG. 10 is a partial cross-sectional view illustrating the method for manufacturing the solid-state imaging device according to the first embodiment of the present invention for each step, and is a continuation of FIG. 10. FIG. 12 is a partial cross-sectional view illustrating the method for manufacturing the solid-state imaging device according to the first embodiment of the present invention for each step and is a continuation of FIG. 11. FIG. 13 is a partial cross-sectional view illustrating the method for manufacturing the solid-state imaging device according to the first embodiment of the present invention for each process, and is a continuation of FIG. 12. FIG. 14 is a partial cross-sectional view illustrating the method for manufacturing the solid-state imaging device according to the first embodiment of the present invention for each step, and is a continuation of FIG. 13. FIG. 15 is a partial cross-sectional view illustrating the method for manufacturing the solid-state imaging device according to the first embodiment of the present invention for each process, and is a continuation of FIG. 14. In the manufacturing method of the solid-state imaging device concerning a 1st embodiment of the present invention, it is a top view showing a plurality of imaging device parts arranged in the shape of a matrix on a silicon wafer. It is principal part sectional drawing which shows schematic structure of the solid-state imaging device which concerns on 2nd Embodiment of this invention. It is a fragmentary sectional view which shows the manufacturing method of the solid-state imaging device which concerns on 2nd Embodiment of this invention for every process. FIG. 19 is a partial cross-sectional view illustrating the method for manufacturing the solid-state imaging device according to the second embodiment of the present invention for each step, and is a continuation of FIG. 18. FIG. 20 is a partial cross-sectional view illustrating the method for manufacturing the solid-state imaging device according to the second embodiment of the present invention for each process, and is a continuation of FIG. 19. FIG. 21 is a partial cross-sectional view illustrating the method for manufacturing the solid-state imaging device according to the second embodiment of the present invention for each process, and is a continuation of FIG. 20. FIG. 22 is a partial cross-sectional view illustrating the method for manufacturing the solid-state imaging device according to the second embodiment of the present invention for each step, which is a continuation of FIG. 21. FIG. 23 is a partial cross-sectional view illustrating the method for manufacturing the solid-state imaging device according to the second embodiment of the present invention for each process, and is a continuation of FIG. 22. FIG. 24 is a partial cross-sectional view illustrating the method of manufacturing the solid-state imaging device according to the second embodiment of the present invention for each process, and is a continuation of FIG. 23. FIG. 25 is a partial cross-sectional view illustrating the method for manufacturing the solid-state imaging device according to the second embodiment of the present invention for each process, and is a continuation of FIG. 24. FIG. 26 is a partial cross-sectional view illustrating the method for manufacturing the solid-state imaging device according to the second embodiment of the present invention for each step, which is a continuation of FIG. 25. It is principal part sectional drawing which shows schematic structure of the solid-state imaging device which concerns on 3rd Embodiment of this invention. It is a fragmentary sectional view which shows the manufacturing method of the solid-state imaging device which concerns on 3rd Embodiment of this invention for every process. FIG. 29 is a partial cross-sectional view illustrating the method of manufacturing the solid-state imaging device according to the third embodiment of the present invention for each process, and is a continuation of FIG. 28. FIG. 29 is a partial cross-sectional view illustrating the method of manufacturing the solid-state imaging device according to the third embodiment of the present invention for each process, and is a continuation of FIG. 29. It is a fragmentary sectional view which shows the manufacturing method of the solid-state imaging device concerning 3rd Embodiment of this invention for every process, and is a continuation of FIG. FIG. 32 is a partial cross-sectional view illustrating the method for manufacturing the solid-state imaging device according to the third embodiment of the present invention for each step, and is a continuation of FIG. 31.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 1A, 1B Solid-state imaging device 2 Imaging device part 10 Solid-state image sensor 11 Silicon substrate 11a Through-hole of silicon substrate and silicon wafer 11A Silicon wafer 12 Interlayer insulating film 12a Through-hole of interlayer insulating film 13 Inter-layer insulating film 14 Through-hole 15 surface electrode 17 micro color filter 18 microlens array 18a microlens 22 SiO ₂ film 22a SiO ₂ film through-hole 23 SiO ₂ film 24 wiring film 25 external electrodes 25a external electrode filled portion 25b electrode portion 26 gap 27 SiO external electrodes of the ₂ film 28 SiN _x film 29 SiO ₂ film 30 Adhesive film 31 Through hole 40 Glass cover 40A Glass plate 50 Insulating synthetic resin 51 Mask 51A Mask through hole 52 Mask 53a, 53b Scribe line 54 Mask 54A Mask through hole S Imaging surface

Claims (16)

A semiconductor device having a through conductor penetrating a semiconductor substrate,
A semiconductor substrate having a predetermined element or circuit formed on the front surface side and having a through hole penetrating from the front surface side to the back surface side;
A surface electrode electrically connected to the element or circuit, formed at a position overlapping the through hole on the surface side of the semiconductor substrate;
A first insulating film that covers the inner surface of the through hole and the back surface of the semiconductor substrate, and has a through hole that reaches the back surface of the front electrode inside the through hole;
A wiring film formed in a predetermined pattern on the first insulating film, and in contact with the back surface of the front surface electrode through the through hole in the through hole;
An external electrode formed on the wiring film, and the external electrode has a filling portion that fills a void remaining inside the wiring film inside the through hole,
A portion of the wiring film in the through hole and the filling portion function as the through conductor.   The first insulating film is formed directly on the inner surface of the through hole inside the through hole, and the second insulating film is formed between the back surface of the semiconductor substrate and the first insulating film outside the through hole. The semiconductor device according to claim 1, wherein:   The first insulating film is formed directly on the inner surface of the through hole inside the through hole, and the first insulating film is formed directly on the back surface of the semiconductor substrate outside the through hole. The semiconductor device according to claim 1.   A second insulating film that covers the inner side surface of the through hole and the back surface of the semiconductor substrate and has a through hole reaching the back surface of the front surface electrode inside the through hole overlaps the first insulating film. The semiconductor device according to claim 1, wherein the semiconductor device is formed.   A second insulating film that covers the inner side surface of the through hole and the back surface of the semiconductor substrate and has a through hole reaching the back surface of the front surface electrode inside the through hole overlaps the first insulating film. A third insulating film that is formed and covers the inner side surface of the through hole and the back surface of the semiconductor substrate, and has a through hole reaching the back surface of the front electrode inside the through hole, the second insulating film The semiconductor device according to claim 1, wherein the semiconductor device is formed so as to overlap.   The semiconductor device according to claim 1, wherein the external electrode is formed of a plated metal.   The thickness of the said 1st insulating film on the inner surface of the said through-hole is set smaller than the thickness on the back surface of the said semiconductor substrate of the said 1st insulating film. The semiconductor device described.   The semiconductor device according to claim 1, wherein the semiconductor device is a solid-state imaging device. A method for manufacturing a semiconductor device having a through conductor penetrating a semiconductor substrate,
A semiconductor substrate having a predetermined element or circuit formed on the surface side and a surface electrode electrically connected to the element or circuit on the surface side is prepared,
Selectively removing the semiconductor substrate from its back side, forming a through-hole that reaches the surface electrode through the semiconductor substrate from its back side to the front side;
Forming a first insulating film from the back surface side of the semiconductor substrate, covering the back surface of the semiconductor substrate, the inner surface of the through hole, and the back surface of the surface electrode;
By selectively removing a portion of the first insulating film on the back surface of the front surface electrode from the back surface side of the semiconductor substrate, a through hole reaching the back surface of the front surface electrode is formed in the first insulating film,
Forming a wiring film in a predetermined pattern on the first insulating film so as to contact the back surface of the front surface electrode through the through hole of the first insulating film inside the through hole;
Forming an external electrode on the surface of the wiring film so as to have a filling portion filling a void remaining inside the through hole;
A method of manufacturing a semiconductor device, wherein a portion inside the through hole of the wiring film and the filling portion function as the through conductor. Inside the through hole, the first insulating film is directly formed on the inner surface of the through hole,
The method for manufacturing a semiconductor device according to claim 9, wherein a second insulating film is formed between the back surface of the semiconductor substrate and the first insulating film outside the through hole.   The first insulating film is directly formed on the inner surface of the through hole inside the through hole, and the first insulating film is directly formed on the back surface of the semiconductor substrate outside the through hole. Item 10. A method for manufacturing a semiconductor device according to Item 9.   A second insulating film that covers the inner side surface of the through hole and the back surface of the semiconductor substrate and has a through hole reaching the back surface of the front surface electrode inside the through hole overlaps the first insulating film. The method for manufacturing a semiconductor device according to claim 9, which is formed. A second insulating film that covers the inner side surface of the through hole and the back surface of the semiconductor substrate and has a through hole reaching the back surface of the front surface electrode inside the through hole overlaps the first insulating film. Formed,
A third insulating film that covers the inner surface of the through hole and the back surface of the semiconductor substrate and has a through hole that reaches the back surface of the front surface electrode inside the through hole overlaps the second insulating film. The method for manufacturing a semiconductor device according to claim 9, which is formed.   The method of manufacturing a semiconductor device according to claim 9, wherein the external electrode is formed by a conductive metal plating method.   After forming the first insulating film so as to cover the back surface of the surface electrode, the inner surface of the through-hole, and the back surface of the semiconductor substrate, the first insulating film is anisotropically etched without a mask. The method for manufacturing a semiconductor device according to claim 9, wherein only the portion on the back surface of the front surface electrode is selectively removed to form the through hole. The method of manufacturing a semiconductor device according to claim 9, wherein the semiconductor device is a solid-state imaging device.

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