JP2008155326A - Semiconductor device and manufacturing method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a semiconductor device which enhances reliability by improving bonding strength between respective substrates, and to provide a manufacturing method therefor. <P>SOLUTION: On one surface of a sensor wafer 10 obtained by forming a plurality of sensor substrates 1 being first substrates, a first package wafer 20 obtained by forming a plurality of through-hole wiring formation substrates 2 being second substrates, is laminated. On the other surface, a second package wafer 30 obtained by forming a plurality of cover substrates 3 being third substrates, is laminated. In each of the plurality of the laminated sensor substrates 1, through-hole wiring formation substrates 2, and cover substrates 3, a through-hole is formed. The inside of the through-hole is filled with a connecting member, and then, the dicing into respective chips is performed. <P>COPYRIGHT: (C)2008,JPO&amp;INPIT

Description

  The present invention relates to a semiconductor device and a manufacturing method thereof.

Conventionally, a micro device package as disclosed in Japanese Patent Laid-Open No. 2001-129800 (Patent Document 1) is known. As shown in FIG. 14, the micro device package includes a functional micro device 32 as a first substrate, and a substrate with feedthrough as second and third substrates stacked on both sides of the functional micro device 32. It consists of 31. The functional microdevice 32 is packaged by being sandwiched between the field-through bump substrates 31 which are the second and third substrates, and a micropackage having functions such as a micromachine sensor and an actuator is manufactured.
JP 2001-129800 A

  However, in the above-described conventional microdevice package disclosed in Japanese Patent Application Laid-Open No. 2001-129800, the functional microdevice 32 that is the first substrate and the feed that is the second substrate provided on the upper side. A substrate 31a with through and a substrate 31b with feedthrough, which is a third substrate provided below, are bonded and packaged at the wafer level, respectively. Thereafter, in the step of dicing the packaged micro device package into each chip, there is a problem in that the bonding interface peels off due to insufficient bonding strength between the substrates, and the yield rate of chips in the wafer surface decreases.

  The present invention has been invented in view of the above-described background art, and its object is to provide a semiconductor device capable of improving reliability by improving the bonding strength between the substrates, and a method for manufacturing the semiconductor device. That is.

  In order to solve the above-described problem, in the invention according to claim 1 of the present application, a first package wafer having a plurality of second substrates formed thereon is stacked on one surface of a sensor wafer having a plurality of first substrates formed thereon, and the other A second package wafer having a plurality of third substrates formed thereon is stacked, a through hole is formed in each of the stacked first, second, and third substrates, and a connecting member is formed in the through hole. It is characterized by dicing each chip after filling.

  In the invention according to claim 2 of the present application, a first substrate formed of a semiconductor substrate on which an electronic device is formed, a second substrate disposed on one surface of the first substrate, and a first substrate A third substrate disposed on the other surface, a through hole formed through the first, second and third substrates, and a first, second and second provided in the through hole; And a connecting member for connecting the three substrates.

  According to a third aspect of the present invention, in the semiconductor device according to the second aspect, the through hole of the second substrate and / or the third substrate has a side facing the first substrate. Is formed with an enlarged-diameter hole at the opposite end, and the connecting member is characterized in that the enlarged-diameter part is provided at a position corresponding to the enlarged-diameter hole.

  In the invention according to claim 4 of the present application, in the semiconductor device according to claim 3, the inner diameter surface is formed in a step shape so that the inner diameter becomes smaller as the inner diameter approaches the first substrate, The enlarged diameter portion is characterized in that a step shape corresponding to the step shape is formed so that the outer diameter increases as it approaches the tip.

  In the invention according to claim 5 of the present application, in the semiconductor device according to claim 3, the enlarged-diameter hole portion is formed by inclining the inner peripheral surface so that the inner diameter becomes smaller as it approaches the first substrate, The enlarged diameter portion is characterized in that an inclined shape corresponding to the inclined shape of the enlarged diameter hole portion is formed so that the outer diameter increases as it approaches the tip.

  According to a sixth aspect of the present invention, in the semiconductor device according to the second aspect, the through hole of either or both of the second substrate and the third substrate has a concave shape and a convex shape on the inner peripheral surface. Both or any one of these is formed, and the connection member is characterized in that both or one of a convex shape and a concave shape is formed at a position corresponding to the concave and the convex.

  According to a seventh aspect of the present invention, in the semiconductor device according to any one of the second to sixth aspects, the connection member is made of a conductive material in whole or in part, and the connection member is an electronic device. It is characterized in that it is used as a wiring for guiding an electric signal from the outside to the outside.

  The invention according to claim 8 of the present application is characterized in that, in the semiconductor device according to claim 7, the connecting member has a central portion made of a thermosetting resin and an outer peripheral portion made of a conductive material. .

  The invention according to claim 9 of the present application is characterized in that, in the semiconductor device according to any one of claims 2 to 6, the connecting member is made of a thermosetting resin.

  According to the invention of claim 10 of the present application, in the method of manufacturing a semiconductor device according to claim 1, the through hole is formed by dry etching, and both the concave and the convex are formed on the inner peripheral surface of the through hole during the dry etching. Either one is formed.

  In the method of manufacturing a semiconductor device according to the first aspect of the present invention, a first package wafer having a plurality of second substrates formed thereon is stacked on one surface of a sensor wafer having a plurality of first substrates formed thereon, and the other surface. A second package wafer having a plurality of third substrates formed thereon is stacked, a through hole is formed in each of the stacked first, second and third substrates, and a connecting member is provided in the through hole. After filling, each chip is diced. Accordingly, since the connecting member can be interposed in the stacked substrates, it is possible to improve the bonding strength between the substrates in the process of dicing each chip. Thereby, the yield of the semiconductor device can be improved and the reliability can be improved.

  In the semiconductor device according to the second aspect of the present invention, the first, second, and third through holes formed through the first, second, and third substrates and the first, second, and third holes provided in the through holes are provided. By having the connecting member that connects the substrates, the connecting member can provide an effect of assisting the bonding between the substrates, whereby the bonding strength between the substrates can be improved. As a result, the yield of the semiconductor device can be improved and the reliability can be improved.

  In the semiconductor device according to the third aspect of the present invention, in particular, a diameter-expanded hole portion is formed in the end portions of the second substrate and the third substrate, and the connecting member corresponds to the diameter-expanded hole portion. Since the enlarged diameter portion is provided at the position, the enlarged diameter hole portion is larger than the cross-sectional area of other portions of the through holes of the second and third substrates. This makes it difficult for the connecting member to move within the through-hole when the enlarged-diameter portion abuts against the bottom of the enlarged-hole portion, reducing the risk of the connecting member coming out of the through-hole, and further increasing the bonding strength. Can be improved.

  In the semiconductor device according to the fourth aspect of the present invention, in particular, the enlarged-diameter hole portion has an inner peripheral surface formed in a step shape, and the enlarged diameter portion forms a step shape at a position corresponding to the step shape. Therefore, each step of the enlarged diameter portion comes into contact with the bottom of each step of the enlarged diameter hole portion. This makes it more difficult for the connecting member to move within the through hole, reduces the risk of the connecting member coming out of the through hole, and further improves the bonding strength.

  In the semiconductor device according to the fifth aspect of the present invention, in particular, the enlarged hole portions of the second substrate and the third substrate are inclined on the inner peripheral surface so that the inner diameter becomes smaller as the first substrate is approached. Therefore, the enlarged diameter portion is larger than the opening area of the surface of the through hole of the second and third substrates facing the first substrate. Thereby, the possibility that the connecting member may come out of the through hole is reduced, and the bonding strength can be further improved.

  In the semiconductor device according to the sixth aspect of the present invention, in particular, at least one of a concave shape and a convex shape is formed on the inner peripheral surfaces of the through holes provided in the second and third substrates, and the outer peripheral surface of the connecting member. Since the convex shape or the concave shape corresponding to the concave shape or the convex shape provided on the inner peripheral surface of the through hole is provided, the concave shape and the convex shape are fitted to each other. This makes it difficult for the connecting member to move within the through hole, and further improves the bonding strength.

  In the semiconductor device according to the seventh aspect of the present invention, in particular, all or part of the connecting member is made of a conductive material, and the connecting member is used as a wiring for guiding an electrical signal from the electronic device to the outside. Therefore, it is not necessary to separately provide an external extraction wiring, and the number of parts can be reduced.

  In the semiconductor device according to claim 8 of the present application, in particular, since the connecting member is made of a thermosetting resin, the hardness of the connecting member can be increased by applying heat treatment to the connecting member. An effect of improving the bonding strength between the substrates can be added.

  In the semiconductor device according to the ninth aspect of the present invention, in particular, since the connecting member is formed of the thermosetting resin at the center and the conductive material at the outer peripheral portion, an external lead-out wiring is separately provided. There is no need, and the number of parts can be reduced. Furthermore, since the strength of the connecting member can be improved by applying heat treatment to the thermosetting resin, an effect of further improving the bonding strength can be added.

  In the method of manufacturing a semiconductor device according to claim 10 of the present invention, in particular, portions corresponding to the second and third substrates of the through hole are formed by dry etching, and the inside of the through hole is formed during the dry etching. Concavities and convexities are formed on the peripheral surface. As a result, the concave shape and the convex shape of the through hole and the connecting member are fitted to each other, and the possibility that the connecting member comes out of the through hole is reduced, and the joint strength can be further improved.

  1 to 12 show a semiconductor device and a manufacturing method thereof according to the first embodiment of the present invention. As shown in FIGS. 1 to 12, the manufacturing method of the semiconductor device A of the present embodiment is a through hole that is a second substrate on one surface of a sensor wafer 10 in which a plurality of sensor substrates 1 that are first substrates are formed. A first package wafer 20 having a plurality of wiring formation substrates 2 formed thereon is laminated, and a second package wafer 30 having a plurality of cover substrates 3 as third substrates formed on the other surface is laminated. A through hole 4 is formed in each of the sensor substrate 1, the through hole wiring formation substrate 2, and the cover substrate 3, and after the filling member 5 is filled in the through hole 4, dicing is performed on each chip. In addition, the semiconductor device A of the present embodiment is arranged by being stacked on one surface of the sensor substrate 1 that is a first substrate made of a semiconductor substrate on which an electronic device is formed, and the sensor substrate 1 that is the first substrate. A through-hole wiring forming substrate 2 as a second substrate, a cover substrate 3 as a third substrate disposed on the other surface of the sensor substrate 1 as a first substrate, a sensor substrate 1, A through hole 4 formed through the hole wiring forming substrate 2 and the cover substrate 3, a sensor substrate 1 provided in the through hole 4, a connecting member 5 for connecting the through hole wiring forming substrate 2 and the cover substrate 3; It is what has.

  Hereinafter, the semiconductor device and the manufacturing method thereof according to this embodiment will be described in more detail. The semiconductor device of the present embodiment will be described by taking an acceleration sensor formed by using a wafer level packaging technique as an example of a sensor having a chip size package (CSP). As shown in FIG. 1, the acceleration sensor has a sensor wafer 10 in which a plurality of sensor substrates 1 (first substrates) are formed on an SOI wafer and a plurality of through-hole wiring formation substrates 2 (second substrates) in a silicon wafer. After forming the wafer level package structure 100 by bonding the first package wafer 20 and the second package wafer 30 in which a plurality of cover substrates 3 (third substrates) are formed on a silicon wafer at the wafer level. The acceleration sensor shown in FIG. 1C is formed by dividing the sensor substrate 1 into the size of the sensor substrate 1 by a dicing process (a cross section of a portion surrounded by a circle A in the wafer level package structure 100 shown in FIG. 1A). Is equivalent). Therefore, the through-hole wiring forming substrate 2 and the cover substrate 3 have the same outer size as the sensor substrate 1, and a small chip size package can be realized and manufacture is facilitated. As can be seen from the above description, the first package wafer 20 is electrically connected to the gauge resistance of the sensor substrate 1 for each region corresponding to the sensor substrate 1 (that is, for each first package substrate portion). A through-hole wiring 24 is formed.

  The sensor substrate 1 described above processes an SOI wafer having an n-type silicon layer (active layer) 10c on an insulating layer (buried oxide film) 10b made of a silicon oxide film on a support substrate 10a made of a silicon substrate. The through-hole wiring forming substrate 2 is formed by processing the first silicon wafer, and the cover substrate 3 is formed by processing the second silicon wafer. Here, in this embodiment, the thickness of the support substrate 10a in the SOI wafer is about 300 μm to 500 μm, the thickness of the insulating layer 10b is about 0.3 μm to 1.5 μm, and the thickness of the silicon layer 10c is 4 μm to 4 μm. Although the thickness of the first silicon wafer is about 200 μm to 300 μm and the thickness of the second silicon wafer is about 100 to 300 μm, these numerical values are not particularly limited.

  As shown in FIG. 2, the sensor substrate 1 includes a frame portion 11 having a frame shape (in this embodiment, a rectangular frame shape), and a weight portion 12 arranged inside the frame portion 11 is on one surface side (FIG. 1). In FIG. 2 (c) and the upper surface side of FIG. 2 (b), the frame portion 11 is supported so as to be swingable via four flexible strip-like bent portions 13. In other words, the sensor substrate 1 is swingably supported by the frame portion 11 via the four flexure portions 13 in which the weight portion 12 disposed inside the frame-shaped frame portion 11 extends from the weight portion 12 in four directions. Has been. Here, the frame portion 11 is formed using the above-described SOI wafer support substrate 10a, insulating layer 10b, and silicon layer 10c. On the other hand, the bending part 13 is formed using the silicon layer 10c in the above-described SOI wafer, and is sufficiently thinner than the frame part 11.

  The weight part 12 is continuously integrated with each of the rectangular parallelepiped core part 12a supported by the frame part 11 via the four flexure parts 13 and the four corners of the core part 12a when viewed from the one surface side of the sensor substrate 1. And four accompanying portions 12b having a rectangular parallelepiped shape connected to each other. In other words, the weight portion 12 is formed integrally with the core portion 12a and the core portion 12a in which the other end portion of each bending portion 13 whose one end portion is connected to the inner side surface of the frame portion 11 is connected to the outer surface. It has four accompanying parts 12b arranged in the space between the part 12a and the frame part 11. That is, each appendage portion 12b is disposed in a space surrounded by the frame portion 11 and the core portion 12a and the two bent portions 13 and 13 extending in a direction orthogonal to each other when viewed from the one surface side of the sensor substrate 1. In addition, a slit 14 is formed between each of the accompanying portions 12b and the frame portion 11, and the interval between the adjacent accompanying portions 12b with the bending portion 13 interposed therebetween is longer than the width dimension of the bending portion 13. Yes.

  Here, the core portion 12a is formed using the above-described SOI wafer support substrate 10a, the insulating layer 10b, and the silicon layer 10c, and each accompanying portion 12b is formed using the SOI wafer support substrate 10a. It is. Thus, the surface of each associated portion 12b on the one surface side of the sensor substrate 1 is from the plane including the surface of the core portion 12a to the other surface side of the sensor substrate 1 (FIG. 1 (c) and FIG. 2 (b)). (Lower surface side). Note that the above-described frame portion 11, weight portion 12, and each bending portion 13 of the sensor substrate 1 may be formed using a lithography technique and an etching technique.

  By the way, as shown in the lower right of FIGS. 2A and 2B, one direction along one side of the frame portion 11 in the plane parallel to the one surface of the sensor substrate 1 is the positive direction of the x axis. If one direction along the side orthogonal to the one side is defined as the positive direction of the y-axis and one direction of the thickness direction of the sensor substrate 1 is defined as the positive direction of the z-axis, the weight portion 12 is extended in the x-axis direction. The pair of flexible portions 13 and 13 sandwiching the core portion 12a and the pair of flexible portions 13 and 13 extending in the y-axis direction and sandwiching the core portion 12a are supported by the frame portion 11. Will be. In the orthogonal coordinates defined by the three axes of the above-described x axis, y axis, and z axis, the center position of the weight portion 12 on the surface of the portion of the sensor substrate 1 formed by the silicon layer 10c is the origin.

  The bent portion 13 (the bent portion 13 on the right side of FIG. 2A) extended from the core portion 12a of the weight portion 12 in the positive direction of the x-axis is a pair of piezoresistors Rx2 and Rx4 in the vicinity of the core portion 12a. Is formed, and one piezoresistor Rz2 is formed in the vicinity of the frame portion 11. On the other hand, the bending portion 13 (the bending portion 13 on the left side of FIG. 2A) extending from the core portion 12a of the weight portion 12 in the negative direction of the x-axis is a pair of piezoresistors Rx1 in the vicinity of the core portion 12a. , Rx3 are formed, and one piezoresistor Rz3 is formed in the vicinity of the frame portion 11. Here, the four piezoresistors Rx1, Rx2, Rx3, and Rx4 formed in the vicinity of the core portion 12a are formed to detect acceleration in the x-axis direction, and the planar shape is an elongated rectangular shape. The wiring is formed so that the longitudinal direction thereof coincides with the longitudinal direction of the bending portion 13, and the wiring (the diffusion layer wiring formed on the sensor substrate 1, the metal wiring 17 is formed so as to constitute the left bridge circuit Bx in FIG. 3. Etc.). Note that the piezoresistors Rx1 to Rx4 are formed in a stress concentration region where stress is concentrated in the bent portion 13 when acceleration in the x-axis direction is applied.

  Further, the bending portion 13 (the upper bending portion 13 in FIG. 2A) extended from the core portion 12a of the weight portion 12 in the positive direction of the y-axis is a pair of piezoresistors Ry1, in the vicinity of the core portion 12a. Ry3 is formed, and one piezoresistor Rz1 is formed in the vicinity of the frame portion 11. On the other hand, the bending portion 13 (the lower bending portion 13 in FIG. 2A) extended from the core portion 12a of the weight portion 12 in the negative direction of the y-axis is a pair of piezoresistors Ry2 in the vicinity of the core portion 12a. , Ry4 are formed, and one piezoresistor Rz4 is formed at the end on the frame part 11 side. Here, the four piezoresistors Ry1, Ry2, Ry3, and Ry4 formed in the vicinity of the core portion 12a are formed to detect acceleration in the y-axis direction, and the planar shape is an elongated rectangular shape. The wiring is formed so that the longitudinal direction coincides with the longitudinal direction of the flexure 13 and wiring (diffuse layer wiring formed on the sensor substrate 1, metal wiring 17 is formed so as to constitute the central bridge circuit By in FIG. 3. Etc.). Note that the piezoresistors Ry1 to Ry4 are formed in a stress concentration region where stress is concentrated in the bent portion 13 when acceleration in the y-axis direction is applied.

  Further, the four piezoresistors Rz1, Rz2, Rz3, Rz4 formed in the vicinity of the frame portion 11 are formed for detecting acceleration in the z-axis direction, and constitute the right bridge circuit Bz in FIG. Thus, they are connected by wiring (a diffusion layer wiring formed on the sensor substrate 1, a metal wiring 17 or the like). However, the piezoresistors Rz1 and Rz4 formed in one set of the bent portions 13 and 13 of the two bent portions 13 and 13 are formed so that the longitudinal direction thereof coincides with the longitudinal direction of the bent portions 13 and 13. On the other hand, the piezoresistors Rz2 and Rz3 formed in the other set of flexures 13 and 13 are formed such that the longitudinal direction coincides with the width direction (short direction) of the flexures 13 and 13. Yes.

  1 and 2, only the portion in the vicinity of the first connection bonding metal layer 19 in the metal wiring 17 in the sensor substrate 1 is illustrated, and the diffusion layer wiring is not illustrated.

  As shown in FIG. 4, the through-hole wiring forming substrate 2 includes a plurality of (this embodiment) electrically connected to the respective through-hole wirings 24 on the periphery of the displacement space forming concave portion 21 on the surface on the sensor substrate 1 side. In the embodiment, eight) second connecting bonding metal layers 29 are formed. The through-hole wiring forming substrate 2 has a frame-shaped (rectangular frame-shaped) second sealing bonding metal layer 28 formed around the entire periphery of the surface on the sensor substrate 1 side. The eight second connecting bonding metal layers 29 have a rectangular shape whose outer peripheral shape is an elongated shape, and are disposed on the inner side of the second sealing bonding metal layer 28. Here, one end of the second connection bonding metal layer 29 is bonded to the through-hole wiring 24, and the other end side is outside the metal wiring 17 of the sensor substrate 1 and the sensor substrate 1. The first connecting bonding metal layer 19 is bonded and electrically connected. In short, the positions of the through-hole wiring 24 and the first connecting bonding metal layer 19 corresponding to the through-hole wiring 24 are shifted in the circumferential direction of the through-hole wiring forming substrate 2, and the second connecting bonding metal layer 29 is arranged such that the longitudinal direction thereof coincides with the circumferential direction of the second sealing bonding metal layer 28 and straddles the through-hole wiring 24 and the first connecting bonding metal layer 19.

  The second sealing bonding metal layer 28 and the second connecting bonding metal layer 29 have a Ti film for improving adhesion between the bonding Au film and the insulating film 23. In other words, the second sealing bonding metal layer 28 and the second connecting bonding metal layer 29 are a laminated film of a Ti film formed on the insulating film 23 and an Au film formed on the Ti film. It is comprised by. In short, since the second connecting bonding metal layer 29 and the second sealing bonding metal layer 28 are formed of the same metal material, the second connecting bonding metal layer 29 and the second sealing metal layer 29 are formed. The joint metal layer 28 can be formed at the same time, and the second joint metal layer 29 for connection and the second joint metal layer 28 for sealing can be formed to have substantially the same thickness. The second sealing bonding metal layer 28 and the second connecting bonding metal layer 29 have a Ti film thickness of 15 to 50 nm and an Au film thickness of 500 nm. The numerical value is an example and is not particularly limited. Here, the material of each Au film is not limited to pure gold, and may be added with impurities. In the present embodiment, a Ti film is interposed as an adhesion improving adhesive layer between each Au film and the insulating film 23. However, the material of the adhesion layer is not limited to Ti, and, for example, Cr, Nb Zr, TiN, TaN, etc. may be used.

  A plurality of external connection electrodes 25 electrically connected to the respective through-hole wirings 24 are formed on the surface of the through-hole wiring forming substrate 2 opposite to the sensor substrate 1 side. The outer peripheral shape of each external connection electrode 25 is rectangular.

As shown in FIG. 5, the cover substrate 3 is formed with a concave portion 31 having a predetermined depth (for example, about 5 μm to 10 μm) that forms a displacement space of the weight portion 12 on the surface facing the sensor substrate 1.
Here, the recess 31 is formed using a lithography technique and an etching technique. In the present embodiment, the concave portion 31 that forms the displacement space of the weight portion 12 is formed on the surface of the cover substrate 3 facing the sensor substrate 1 (that is, the concave portion 31 is formed for each second package substrate portion. However, the thickness of the portion formed using the support substrate 10a of the core portion 12a and the associated portion 12b of the weight portion 12 is determined using the support substrate 10a in the frame portion 11. If the thickness of the weight portion 12 in the thickness direction of the sensor substrate 1 is made thinner by the allowable displacement amount than the thickness of the formed portion, the sensor can be obtained without forming the recess 31 in the cover substrate 3. On the other surface side of the substrate 1 is a weight 12 in a direction intersecting the other surface.
A gap that allows this displacement is formed between the weight 12 and the cover substrate 3.

  As shown in FIG. 1, a sensor board 1 that is a body of an acceleration sensor and a through hole wiring 24 that is electrically connected to a gauge resistance of the sensor board 1 and sealed on one surface side of the sensor board 1 A hole wiring forming substrate 2 and a cover substrate 3 sealed on the other surface side of the sensor substrate 1 are provided. Here, the outer peripheral shapes of the sensor substrate 1, the through-hole wiring formation substrate 2, and the cover substrate 3 are rectangular, and the through-hole wiring formation substrate 2 and the cover substrate 3 are formed to have the same outer dimensions as the sensor substrate 1.

  Here, as shown in FIGS. 2, 4, and 5, the sensor substrate 1, the through-hole wiring forming substrate 2, and the through-hole 4 formed through the cover substrate 3, and the through-hole 4 are provided. The sensor board 1, the through hole wiring forming board 2, and the connecting member 5 for connecting the cover board 3 are formed, and the through hole 4 and the connecting member 5 are formed in the vicinity of each corner of each board. . In the example shown in FIGS. 2, 4, and 5, the cross-sectional shape of the through hole 4 is a circular shape, but is not limited to this, and may be an elliptical shape or a polygonal shape.

  FIG. 6B shows a DD cross section of FIG. 6A of the through hole 4 and the connecting member 5. The through holes 4 are provided at four locations near the corners where the sensor substrate 1, the through hole wiring formation substrate 2 and the cover substrate 3 are joined to each other and where there are no electronic components and wirings. A connecting member 5 filled with a conductive material (such as copper or nickel) without gaps is interposed in the through hole 4. Furthermore, an electrode pad 50 connected to the end of the connecting member 5 is provided on the surface of the through hole wiring forming substrate 2 or the cover substrate 3 opposite to the surface facing the sensor substrate 1. Further, in the connecting member 5 interposed in the through hole 4 formed so as to penetrate the sensor substrate 1, the through hole wiring formation substrate 2 and the cover substrate 3, the first connecting metal layer 19 for connection (see FIG. 6B). By connecting the second connecting bonding metal layer 29 (not shown in FIG. 6B), it is electrically connected to the gauge resistance of the sensor substrate 1. This makes it possible to take out electrical signals to both sides of the through-hole wiring forming substrate 2 and the cover substrate 3 without adding new components. Insulating properties can be maintained by forming an insulating film 6 between the through hole 4 and the connecting member 5.

  Accordingly, the through hole 4 formed through the sensor substrate 1, the through hole wiring formation substrate 2 and the cover substrate 3, and the sensor substrate 1, the through hole wiring formation substrate 2 and the cover substrate 3 provided in the through hole 4. By having the connecting member 5 that connects the two, the connecting member 5 has an effect of assisting the bonding between the substrates, whereby the bonding strength between the substrates can be improved. As a result, the yield of the semiconductor device A can be improved and the reliability can be improved. Further, since the connecting member 5 is made of a conductive material, and the connecting member 5 is used as a wiring for guiding an electric signal from the sensor substrate 1 to the outside, it is not necessary to separately provide an external extraction wiring, and the number of parts can be reduced. Can be reduced.

  Next, a method for manufacturing the semiconductor device shown in this embodiment will be described with reference to FIG. In the example shown here, a conductive member (such as copper or nickel) is used for the connecting member 5. As shown in FIG. 7A, the through-hole wiring forming substrate 2 is laminated on one surface of the sensor substrate 1 by, for example, anodic bonding, diffusion bonding, adhesion by a die bonding material, or the like. The cover substrate 3 is laminated on the other surface, and the substrates are bonded at the wafer level. As shown in FIG. 7 (b), for example, by etching or laser processing, it was laminated at four locations near the corners of each chip size package of the size of the sensor substrate 1 bonded at the wafer level. A through hole 4 penetrating the front and back surfaces of the sensor substrate 1, the through hole wiring formation substrate 2 and the cover substrate 3 is formed. The diameter of the through hole 4 is about 10 μm. Further, as shown in FIG. 7C, on the surface opposite to the side facing the sensor substrate 1 of either the through-hole wiring forming substrate 2 or the cover substrate 3 (here, the cover substrate 3), A metal film 500 such as copper or nickel having a thickness of about 10 μm is formed. As shown in FIG. 7D, copper or nickel is filled into the through hole 4 without a gap by an electrolytic plating method using the metal film 500 as a base end. Filling is performed so that the protrusion 501 of the connecting member 5 having a height of about 10 μm and a diameter of about 30 μm is formed on the surface opposite to the surface on which the metal film 500 is formed. The protrusion 501 is removed by using CMP (Chemical Mechanical Polishing), polishing, etching, or the like. As a result, as shown in FIG. 7E, the connecting member 5 can be formed without protruding the connecting member 5 from the surface of the through-hole wiring forming substrate 2 and the cover substrate 3. And after the connection member 5 is formed in the through-hole 4, it is divided | segmented by the dicing process to the size of the sensor board | substrate 1, and an acceleration sensor is formed.

  Therefore, the second package is formed by laminating the first package wafer 20 having a plurality of through-hole wiring formation substrates 2 formed on one surface of the sensor wafer 10 having a plurality of sensor substrates 1 and forming the plurality of cover substrates 3 on the other surface. Each of the package wafers 30 is stacked, a through hole 4 is formed in each of the stacked sensor substrate 1, through hole wiring forming substrate 2, and cover substrate 3, and the connecting member 5 is filled in the through hole 4. Dicing into chips. As a result, the connecting member 5 can be interposed between the stacked substrates, so that the bonding strength between the substrates can be improved in the step of dicing each chip. Thereby, the yield of the semiconductor device A can be improved and the reliability can be improved.

  FIG. 8 shows a modification of the present embodiment. As shown in FIG. 8, the through-hole wiring forming substrate 2 and the through-hole 4 of the cover substrate 3 are larger in diameter than other portions of the through-hole 4 at the end opposite to the side facing the sensor substrate 1. An enlarged diameter hole 41 is formed. At a position corresponding to the diameter-expanded hole portion 41, the connecting member 5 is provided with a diameter-expanded portion 51 having a larger diameter than other portions. As shown in FIG. 8A, the enlarged diameter portion 51 fills the space of the enlarged diameter hole portion 41 as shown in FIG. 8B even if it is formed smaller than the inner diameter of the enlarged diameter hole portion 41. You may form as follows. When the shape of the enlarged diameter part 51 is formed so as to fill the space of the enlarged diameter hole part 41, the enlarged diameter part 51 is lower than the inner diameter of the enlarged diameter hole part 41, and the bottom part of the enlarged diameter hole part 41. The area abutting on increases. This makes it more difficult for the connecting member 5 to move in the through hole 4, and further reduces the risk of the connecting member 5 coming out of the through hole 4.

  Therefore, the enlarged hole portion 41 is formed at the end portions of the through-hole wiring forming substrate 2 and the cover substrate 3, and the connecting member 5 is provided with the enlarged diameter portion 51 at a position corresponding to the enlarged hole portion 41. Therefore, the enlarged-diameter hole 41 is larger than the cross-sectional area of the other part of the through-hole wiring forming substrate 2 and the through-hole 4 of the cover substrate 3. Thereby, it becomes difficult for the connecting member 5 to move in the through-hole 4 by the diameter-enlarged portion 51 coming into contact with the bottom portion of the enlarged-diameter hole portion 41, and the possibility that the connecting member 5 comes out of the through-hole 4 is reduced. Thus, the bonding strength can be further improved.

  FIG. 9 shows a modification of the present embodiment. As shown in FIG. 9, the inner peripheral surface of the through-hole wiring forming substrate 2 and the cover substrate 3 is formed in a step shape so that the inner diameter becomes smaller as it approaches the first substrate. Further, the enlarged diameter portion 51 of the connecting member 5 is formed with a step shape corresponding to the step shape of the enlarged diameter hole portion 41 so that the outer diameter increases as it approaches the tip. Here, the correspondence relationship between the enlarged diameter hole portion 41 and the enlarged diameter portion 51 is such that the outer diameter of each step of the enlarged diameter portion 51 forming the step shape is the same position as each step of the enlarged diameter hole portion 41. Are formed so as to be the same as the inner diameter of each step. That is, the enlarged diameter portion 51 is formed so as to fill the space of the enlarged diameter hole portion 41.

  Therefore, the inner diameter surface of the enlarged diameter hole portion 41 is formed in a step shape, and the enlarged diameter portion 51 is formed in a step shape at a position corresponding to the step shape. The step abuts against the bottom of each step of the enlarged diameter hole portion 41. This makes it more difficult for the connecting member 5 to move in the through hole 4, reducing the risk of the connecting member 5 coming out of the through hole 4, and further improving the bonding strength.

  FIG. 10 shows a modification of the present embodiment. As shown in FIG. 10, the through-hole wiring forming substrate 2 and the enlarged-diameter hole portion 41 of the cover substrate 3 are formed with the inner peripheral surface inclined so that the inner diameter becomes smaller as it approaches the sensor substrate 1. That is, when the cross-sectional shape of the enlarged diameter hole portion 41 is circular, the enlarged diameter hole portion 41 has a conical shape. Further, the connecting member 5 is provided with an enlarged diameter portion 51 having a shape corresponding to the inclined shape of the enlarged diameter hole portion 41 so that the outer diameter increases as it approaches the tip. That is, the enlarged diameter portion 51 is formed so as to fill the space of the enlarged diameter hole portion 41. For example, when the enlarged-diameter hole portion 41 forms a conical space, the enlarged-diameter portion 51 also has a conical shape.

  Therefore, since the through-hole wiring forming substrate 2 and the enlarged-diameter hole portion 41 of the cover substrate 3 are formed with the inner peripheral surface inclined so that the inner diameter becomes smaller toward the sensor substrate 1, the enlarged-diameter portion 51 is The opening area of the surface of the through hole wiring forming substrate 2 and the cover substrate 3 plate on the side facing the sensor substrate 1 of the through hole 41 is larger. Thereby, the possibility that the connecting member 5 comes out of the through hole 4 is reduced, and the bonding strength can be further improved.

  FIG. 11 shows a modification of the present embodiment. As shown in FIG. 11, the through-hole wiring forming substrate 2 and the through-hole 4 of the cover substrate 3 have an uneven hole portion 42 in which both or one of a concave shape and a convex shape is formed on the inner peripheral surface. Further, the connecting member 5 has a concave or convex shape in which a concave shape or a convex shape is formed at a position corresponding to the concave and convex hole portion 42 formed in the inner peripheral surface of the through hole wiring forming substrate 2 and the through hole 4 of the cover substrate 3. Part 52. That is, a convex shape is formed on the concave / convex portion 52 of the connecting member 5 corresponding to a position where the concave / convex hole portion 42 is formed on the inner peripheral surface of the through hole 4. Further, the concave and convex portion 52 of the connecting member 5 corresponding to the position where the convex shape is formed in the concave and convex hole portion 42 on the inner peripheral surface of the through hole 4 has a concave shape. Each convex shape and concave shape are determined so that the concave shape or convex shape of the concave and convex hole portion 42 of the through hole 4 and the convex shape or concave shape of the concave and convex portion 52 of the connecting member 5 can be fitted to each other. Yes. The convex shape and the concave shape may be formed over the entire length of the portion corresponding to the through-hole wiring forming substrate 2 and the cover substrate 3 of the through-hole 4 or may be formed in part.

  Accordingly, at least one of a concave shape and a convex shape is formed on the inner peripheral surface of the through hole 4 provided in the through hole wiring forming substrate 2 and the cover substrate 3, and the inner peripheral surface of the through hole 4 is formed on the outer peripheral surface of the connecting member 5. Since the convex shape or the concave shape corresponding to the concave shape or the convex shape provided in is provided, the concave shape and the convex shape are fitted to each other. Thereby, the connection member 5 becomes difficult to move in the through hole 4, and the joint strength can be further improved.

  Next, a method for manufacturing the semiconductor device shown in this modification will be described. As shown in FIG. 12A, the through-hole wiring forming substrate 2 is laminated on one surface of the sensor substrate 1 by, for example, anodic bonding, diffusion bonding, adhesion using a die bonding material, or the like. The cover substrate 3 is laminated on the other surface, and the substrates are bonded at the wafer level. As shown in FIG. 12 (b), the sensor substrate 1 stacked in the four positions near the corners of each chip size package of the size of the sensor substrate 1 bonded at the wafer level, as shown in FIG. A through-hole 4 penetrating the front and back surfaces of the hole wiring formation substrate 2 and the cover substrate 3 is formed. The diameter of the through hole 4 is about 10 μm. Here, by adjusting the time and the number of cycles of the etching step and the deposition step during dry etching, as shown in FIG. 12B, the through-hole wiring forming substrate 2 and the cover substrate 3 of the through-hole 4 are formed. An uneven hole portion 42 having an uneven shape called a scallop structure can be formed on the inner surface of the corresponding part.

  Further, as shown in FIG. 12C, copper having a thickness of about 10 μm is formed on the surface of the through hole wiring forming substrate 2 or the cover substrate 3 opposite to the side facing the sensor substrate 1. A metal film 500 such as nickel is formed. As shown in FIG. 12 (d), copper or nickel is filled into the through-hole 4 without a gap by an electrolytic plating method using the metal film 500 as a base end. Filling is performed so that the protrusion 501 of the connecting member 5 having a height of about 10 μm and a diameter of about 30 μm is formed on the surface opposite to the surface on which the metal film 500 is formed. As a result, the metal film 500 is filled in the space of the uneven hole portion 42, and the uneven portion 52 of the connecting member 5 is formed. Further, the protruding portion 501 is removed by using CMP (Chemical Mechanical Polishing), polishing, etching, or the like. As a result, as shown in FIG. 12E, the connecting member 5 can be formed without protruding the connecting member 5 from the surface of the through-hole wiring forming substrate 2 and the cover substrate 3. And after the connection member 5 is formed in the through-hole 4, it is divided | segmented by the dicing process to the size of the sensor board | substrate 1, and an acceleration sensor is formed.

  Therefore, portions corresponding to the through-hole wiring forming substrate 2 and the cover substrate 3 of the through-hole 4 are formed by dry etching, and an uneven hole portion 42 is formed on the inner peripheral surface of the through-hole 4 during the dry etching. Yes. As a result, the uneven portion 52 of the connecting member 5 is formed at a position corresponding to the uneven hole portion 42 of the through hole 4. Therefore, the concave / convex hole portion 42 of the through hole 4 and the concave / convex portion 52 of the connecting member 5 are fitted to each other, and the possibility that the connecting member 5 comes out of the through hole 4 is reduced, and the bonding strength can be further improved.

  Next, a semiconductor device according to a second embodiment of the present invention will be described. Here, only matters different from those in the first embodiment will be described, and other matters (configuration, operational effects, and the like) are the same as those in the first embodiment, and thus description thereof will be omitted.

  The connecting member 5 formed in the through hole 4 penetrating the sensor substrate 1, the through hole wiring forming substrate 2 and the cover substrate 3 is made of a thermosetting resin. Here, about the shape of the through-hole 4 and the connection member 5, it can be set as the shape shown in the said 1st Embodiment of this invention. The connection member 5 is formed by performing the same process as the process of forming the through hole 4 of the manufacturing method shown in the first embodiment of the present invention, and then filling and curing the thermosetting resin. can do. As the thermosetting resin, unsaturated polyester resin (UP), vinyl ester resin (VE), phenol resin (PF), or the like can be used.

  Therefore, since the connecting member 5 is made of a thermosetting resin, the hardness of the connecting member 5 can be increased by applying a heat treatment to the connecting member 5, thereby further improving the bonding strength between the substrates. Can be added.

  FIG. 13 shows a semiconductor device according to the third embodiment of the present invention. Here, only matters different from those in the first embodiment will be described, and other matters (configuration, operational effects, etc.) are the same as those in the first and second embodiments, and thus the description thereof is omitted. .

  As shown in FIG. 13, the connecting member 5 formed in the through hole 4 penetrating the sensor substrate 1, the through hole wiring formation substrate 2 and the cover substrate 3 has a central portion 53 made of a thermosetting resin, The portion 54 is made of a conductive material. Here, the shapes of the through hole 4 and the connecting member 5 can be the shapes shown in the first embodiment of the present invention. Further, a first connecting metal layer 19 for connection (not shown in FIG. 13) or the outer peripheral portion 54 of the connecting member 5 formed penetrating the sensor substrate 1, the through-hole wiring forming substrate 2 and the cover substrate 3 or By connecting the second connecting bonding metal layer 29 (not shown in FIG. 13), it is electrically connected to the gauge resistance of the sensor substrate 1. This makes it possible to take out electrical signals to both sides of the through-hole wiring forming substrate 2 and the cover substrate 3 without adding new components.

  The required hardness of the connecting member 5 can be adjusted by changing the cross-sectional area ratio between the central portion 53 and the outer peripheral portion 54.

  Therefore, since the connection member 5 has the central portion 53 made of a thermosetting resin and the outer peripheral portion 54 made of a conductive material, the outer peripheral portion 54 can be used as an external extraction wiring. As a result, it is not necessary to separately provide external lead-out wiring, and the number of parts can be reduced. Furthermore, since the hardness of the connection member 5 can be improved by applying heat treatment to the thermosetting resin, an effect of further improving the bonding strength between the substrates can be added.

1 shows a wafer level package structure in a semiconductor device according to an embodiment of the present invention, in which (a) is a schematic plan view, (b) is a schematic side view, and (c) is a schematic cross-sectional view of an acceleration sensor. The sensor board | substrate in the semiconductor device is shown, (a) is a schematic plan view, (b) is AA schematic sectional drawing of (a). It is a circuit diagram of a sensor substrate in the semiconductor device. The acceleration sensor in the semiconductor device is shown, (a) is a schematic plan view, (b) is a BB schematic sectional view of (a). The cover board | substrate in the semiconductor device is shown, (a) is a schematic plan view, (b) is CC schematic sectional drawing of (a). The acceleration sensor in the same semiconductor device is shown, (a) is a schematic plan view, (b) is a DD schematic cross-sectional view of (a). It is principal process sectional drawing for demonstrating the manufacturing method of the acceleration sensor in the semiconductor device which is embodiment of this invention. It is a principal part schematic sectional drawing of the acceleration sensor in the semiconductor device which is a modification of embodiment of this invention. It is a principal part schematic sectional drawing of the acceleration sensor in the semiconductor device which is a modification of embodiment of this invention. It is a principal part schematic sectional drawing of the acceleration sensor in the semiconductor device which is a modification of embodiment of this invention. It is a principal part schematic sectional drawing of the acceleration sensor in the semiconductor device which is a modification of embodiment of this invention. It is principal process sectional drawing for demonstrating the manufacturing method of the acceleration sensor in the semiconductor device which is a modification of embodiment of this invention. It is a principal part schematic sectional drawing of the semiconductor device which is the 3rd Embodiment of this invention. It is a schematic sectional drawing of the semiconductor device which is a prior art example.

Explanation of symbols

1 Sensor board (first board)
10 Sensor wafer 2 Through-hole wiring forming substrate (second substrate)
20 First package wafer 3 Cover substrate (third substrate)
DESCRIPTION OF SYMBOLS 30 2nd package wafer 4 Through-hole 41 Expanded-hole part 42 Irregular hole part 5 Connecting member 50 Electrode pad 51 Expanded-diameter part 52 Uneven part 53 Center part 54 Outer part 6 Insulating film 100 Wafer level package structure

Claims (10)

  A first package wafer having a plurality of second substrates formed thereon is laminated on one surface of a sensor wafer having a plurality of first substrates, and a second package wafer having a plurality of third substrates formed on the other surface. Then, a through hole is formed in each of the stacked first, second and third substrates, and a dicing member is diced after filling the through hole with a connecting member. Production method.   A first substrate comprising a semiconductor substrate on which an electronic device is formed; a second substrate disposed on one surface of the first substrate; and a layer disposed on the other surface of the first substrate. A third substrate; a through-hole formed through the first, second, and third substrates; and a connecting member that connects the first, second, and third substrates provided in the through-hole. A semiconductor device comprising:   The through hole of both or any one of the second substrate and the third substrate is formed with a diameter-enlarged hole at the end opposite to the side facing the first substrate, and the connecting member 3. The semiconductor device according to claim 2, wherein an enlarged diameter portion is provided at a position corresponding to the enlarged diameter hole portion.   The enlarged diameter hole portion has an inner peripheral surface formed in a step shape so that the inner diameter becomes smaller as it approaches the first substrate, and the enlarged diameter portion forms the step shape so that the outer diameter increases as it approaches the tip. 4. The semiconductor device according to claim 3, wherein a step shape corresponding to is formed.   The enlarged-diameter hole is formed by inclining the inner peripheral surface so that the inner diameter becomes smaller as it approaches the first substrate, and the enlarged-diameter part is provided with an enlarged diameter so that the outer diameter increases as it approaches the tip. 4. The semiconductor device according to claim 3, wherein an inclined shape corresponding to the inclined shape of the portion is formed.   The through hole of both or any one of the second substrate and the third substrate has a concave shape and / or a convex shape formed on the inner peripheral surface, and the connecting member includes the concave and 3. The semiconductor device according to claim 2, wherein both or one of a convex shape and a concave shape is formed at a position corresponding to the convex.   7. The connection member according to claim 2, wherein the connection member is entirely or partly made of a conductive material, and the connection member is used as a wiring for guiding an electric signal from the electronic device to the outside. The semiconductor device described.   8. The semiconductor device according to claim 7, wherein the connecting member has a central portion made of a thermosetting resin and an outer peripheral portion made of a conductive material.   The semiconductor device according to claim 2, wherein the connecting member is made of a thermosetting resin.   2. The method of manufacturing a semiconductor device according to claim 1, wherein the through hole is formed by dry etching, and at the time of the dry etching, both or one of the concave and convex is formed on the inner peripheral surface of the through hole.

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