JP2002208610A - Bonding pad for integrated circuit, and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bonding pad structure for integrated circuit which can supply a sufficient quantity of current into a chip, while the occurrence of cracks in an interconnecting insulating film is minimized at performing of chip classification and wire bonding, can reduce the quantity of light diffracted in the course of a photo etching process and the peeling of upper wiring from an upper conductive plug due to the repetitive contact of an inspection probe with the wiring, and can improve the reliability of an integrated circuit. SOLUTION: This bonding wire structure includes first and second conductive films which are spaced apart from each other by a prescribed distance, a continuous third conductive film which is provided between the first and second conductive films and electrically connected to the conductive films, and an array insulating islands which exist in the continuous third conductive film and are extended to pass through the third conductive film, in such a way that their sidewalls are covered with the third conductive film, arranged randomly, and separated from each other by a prescribed distance.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an integrated circuit and a method of forming the same, and more particularly, to a bonding pad for an integrated circuit and a method of manufacturing the same.

[0002]

2. Description of the Related Art Integrated circuits called "chips" are widely used in consumer and commercial electronic products. As is well known to those skilled in the art, an integrated circuit generally includes a substrate, such as a semiconductor substrate, and an array of bonding pads on the substrate. The bonding pads electrically connect the outside of the integrated circuit to the microelectronic circuit inside the integrated circuit.

FIG. 1 is a schematic diagram of an integrated circuit package including a plurality of bonding pads. As shown in FIG. 1, an integrated circuit 100, for example, a memory cell array unit 1
The memory integrated circuit including the peripheral circuit unit 115 and the peripheral circuit unit 115 includes a plurality of bonding pads 200. The bonding pad 200 serves as a gate for a circuit terminal of the integrated circuit 100, and is internally connected to an input / output I / O buffer circuit in the peripheral circuit unit 115. As shown in FIG. 1, the integrated circuit 100 is joined to a lead frame 300. Wire bonding or other conventional techniques are used to connect each wire 320 to the bonding pad 200 and the internal lead chip 310 of the lead frame 300.

FIG. 2 shows the bonding pad 200 of FIG.
FIG. FIG. 3 is a perspective view of the bonding pad shown in FIG. FIG. 4 is a cross-sectional view of the bonding pad taken along line IV-IV ′ of FIG.
FIG. 5 is a cross-sectional view of the bonding pad taken along line VV 'of FIG.

As shown in FIGS. 2 to 5, in a conventional bonding pad structure, an independent conductive plug 245, for example, a tungsten plug is used to form a plurality of via holes 240 in an insulating film 250 between wirings. Is filling. The conductive plug 245 is connected to the lower aluminum wiring 23.
0 and the upper aluminum wiring 260 are electrically connected. Reference numeral 210 indicates an integrated circuit substrate, 220 indicates an interlayer insulating film, and 270 indicates a wire bonding region.

[0006]

The structure of the pad shown in FIGS. 2 to 5 has the following problems. For example, at the time of sorting for separating the good integrated circuit 100 from the wafer, the inter-wiring insulating film 250 is formed by a force applied by a probe pin (not shown) of an inspection device placed on the wire bonding region 270.
Cracks in the The crack 330 is also generated in the inter-wiring insulating film 250 due to stress generated by mechanical shock and pressure applied during bonding the wire 320 to the wire bonding region 270.

[0007] The cracks are generated when the relatively soft upper aluminum wiring 260 and lower aluminum wiring 230 are deformed by stress applied during sorting or wire bonding. However, the relatively hard inter-wiring insulating film 250 is not easily deformed. For this reason, when a stress equal to or more than a certain value is applied, the unstable tungsten plug 245 may come off, or the inter-wiring insulating film 250
Cracks in the As shown in FIG. 5, such a crack is caused by the insulating film 2 covering the tungsten plug 245.
Propagated inside 50.

[0008] The cracks generated in the inter-wiring insulating film 250 cause a wiring open problem in which the upper and lower aluminum wirings 260 and 230 are peeled off. Alternatively, the contact between the wire 320 and the upper aluminum wiring 260 becomes poor, and the wire 320 is
The problem of the pad opening peeling off from 60 occurs.

FIG. 6 shows that the cracks in the inter-wiring insulating film are reduced.
In addition, it is a plan view of another conventional bonding pad structure in which a tungsten plug 245 is formed only in a peripheral region outside a central wire bonding region in order to reduce peeling of a wiring film or a wire. FIG.
FIG. 7 is a sectional view of the bonding pad structure taken along the line VII-VII ′ of FIG. 6. The structure of such a bonding pad is disclosed in U.S. Patent Nos. 5,248,903 and 5,5.
02,337.

The bonding pad structure according to FIGS. 6 and 7 and the two patents can reduce cracks in the inter-wiring insulating film 250 to some extent. However, tungsten plug 24
5, the adhesive force between the tungsten plug 245 and the upper aluminum wiring film 260 is weak. As a result, a wiring open phenomenon in which the upper aluminum wiring film 260 is broken at the time of wire bonding frequently occurs. Also, since the number of plugs is reduced, the contact area with the upper aluminum wiring film 260 is reduced, and as a result, the resistance Rs increases and the current decreases. As a result, a sufficient amount of current cannot be supplied to the switching element in the integrated circuit, which causes the operation of the element to deteriorate.

The present invention has been made in view of the above circumstances, and has as its object to supply a sufficient amount of current to a chip while minimizing cracks in an insulating film between wires during chip classification and wire bonding. In addition, the amount of light diffracted during the photolithography process can be reduced, and the phenomenon that the upper wiring separates from the upper conductive plug due to repeated contact with the inspection probe can be reduced, thereby improving the reliability of the integrated circuit. It is to provide a bonding pad structure for a possible integrated circuit.

It is another object of the present invention to supply a sufficient amount of current to a chip while minimizing cracks in an inter-wiring insulating film, and to reduce the amount of light diffracted during a photolithography process. To provide a method suitable for manufacturing a bonding pad structure capable of improving the reliability of an integrated circuit because a phenomenon that an upper wiring is separated from an upper conductive plug due to repeated contact by a test probe can be reduced. It is in.

[0013]

SUMMARY OF THE INVENTION A bonding pad for an integrated circuit according to the present invention includes a first pad spaced a predetermined distance apart.
A conductive film and a second conductive film, the first conductive film being separated from the first conductive film by the predetermined distance;
A continuous third conductive film existing between the conductive film and the second conductive film and electrically connected to the first conductive film and the second conductive film separated by the predetermined distance; A non-aligned, spaced-apart island-shaped insulator that extends within the film and extends through the continuous third conductive film and has sidewalls covered by the continuous third conductive film; And an array of

The array may include a horizontal array of island-shaped insulators that are non-aligned and spaced a predetermined distance and a vertical array that is non-aligned and spaced a predetermined distance. The array of non-aligned and spaced apart island-shaped insulators includes a first island-shaped insulator having a first edge in a first direction and a first island-shaped insulator adjacent to the first direction in the first direction. , A second island-shaped insulator having a second edge in a first direction misaligned with the first edge.

[0015] The bonding pad is present between the continuous third conductive film and the second conductive film, and is electrically connected to the continuous third conductive film and the second conductive film. And a fourth conductive film. A second array of island-shaped insulators separated by a predetermined distance is present in the continuous fourth conductive film, and extends so as to penetrate the continuous fourth conductive film so that sidewalls of the island-shaped insulator are formed. A second array of island-shaped insulators covered by the fourth conductive film and separated by a predetermined distance is non-aligned with the first array of island-shaped insulators separated by a predetermined distance. ing.

[0016] The bonding pad may further include a metal bumper layer on the first conductive film and an upper bonding pad layer on the metal bumper layer formed for bonding to a wire. The metal bumper layer may be tungsten. The metal bumper layer has a thickness of about 4,000.
Å thickness. The metal bumper layer and the upper bonding pad layer may have a thickness of about 12,000 to 14,
It may consist of a single layer having a thickness in the range of 000 °. The upper bonding pad layer may be directly above the metal bumper layer.

The metal bumper layer may include an island-shaped insulator located on an outer edge side of the metal bumper layer. There is no island insulator in the inner region of the metal bumper layer.

The structure of the bonding pad according to the present invention includes a first conductive film and a second conductive film separated by a predetermined distance,
A continuous third conductive film existing between the first conductive film and the second conductive film separated by the predetermined distance and electrically connected to the first conductive film and the second conductive film separated by the predetermined distance; May be included. The structure of the bonding pad is arranged in a zigzag manner in the continuous third conductive film, extends so as to penetrate the continuous third conductive film, and has a side wall formed by the continuous third conductive film. It may further include an array of covered island-shaped insulators at a predetermined distance.

In the method of manufacturing a bonding pad for an integrated circuit according to the present invention, first, a lower conductive film is formed on an integrated circuit substrate. Next, a continuous conductive film electrically connected to the lower conductive film is formed on the lower conductive film.
The continuous conductive film extends inside the continuous conductive film so as to extend through the continuous conductive film, and is separated by a predetermined non-aligned distance in which a sidewall of the island-shaped insulator is covered by the continuous conductive film. Includes array of island insulators. Next, an upper conductive film electrically connected to the continuous conductive film is formed on the continuous conductive film.

The step of forming the continuous conductive film may include the step of forming a continuous conductive film including a horizontal array of island-shaped insulators that are non-aligned and separated by a predetermined distance. The step of forming the continuous conductive layer includes a horizontal array of non-aligned island-shaped insulators spaced apart by a predetermined distance and a vertical array of non-aligned island-shaped insulators spaced by a predetermined distance. May be included.

The step of forming the continuous conductive film includes forming a first island-shaped insulator having a first edge in a first direction in the continuous conductive film. Forming a second island insulator in the continuous conductive film having a second edge in a first direction adjacent to the first island insulator and non-aligned with the first edge. .

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail by describing preferred embodiments of the present invention with reference to the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, and can be embodied in various different forms. This embodiment is provided merely to complete the disclosure of the present invention and to make those skilled in the art completely aware of the scope of the present invention. In the accompanying drawings, the thickness of various films and regions are exaggerated for clarity. Also, when a film is described as being on another film or substrate, one film may be directly on the other film or substrate, or an interlayer film may be between them. In the drawings, the same reference numerals represent the same elements.

FIG. 8 is a plan view of the bonding pad structure according to the first embodiment of the present invention. FIG. 9 is a perspective view of the bonding pad structure shown in FIG.
FIG. 11 is a cross-sectional view of the bonding pad structure taken along the line XX ′ of FIG. 8, and FIG. 11 is a cross-sectional view of the bonding pad structure taken along the line XI-XI ′ of FIG.

In FIG. 8, reference numeral 920 indicates a lower wiring, 925I indicates a lower island-shaped insulator, 930 indicates a lower integrated conductive plug, and 940 indicates an intermediate wiring. Reference numeral 945I denotes an upper island insulator, 950 denotes an upper integrated conductive plug, 960 denotes an uppermost wiring, and 970 denotes a wire bonding region. Reference numerals 925 and 945 denote interlayer insulating films covering the outer walls of the lower and upper integrated conductive plug patterns, respectively. An integral conductive plug may also be referred to as a continuous conductive film. The wiring is called a conductive film, and the island-shaped insulator is called an insulating island. Terms such as "upper" / "lower" and "upper" / "lower" do not indicate an absolute direction but a relative relationship between being adjacent to or away from the integrated circuit substrate. It is.

Referring to FIGS. 9, 10 and 11, an interlayer insulating film 910 is formed on an integrated circuit substrate 900, and a lower wiring 920 and an intermediate wiring 9 are formed on the interlayer insulating film 910.
A bonding pad structure having a three-layer wiring including the uppermost wiring 960 and the uppermost wiring 960 is formed. Top wiring 96
0 comprises a wire bonding area 970 to which the wire 990 is bonded. The wire 990 can serve as a gate of a circuit terminal connected to an input / output buffer circuit (refer to 115 in FIG. 1) which forms a peripheral circuit.

The lower surface of the uppermost wiring 960 and the intermediate wiring 940
An upper integrated conductive plug 950 is arranged between the upper wiring 960 and the upper wiring, and electrically connects the uppermost wiring 960 and the intermediate wiring 940. At least one or more upper island-shaped insulating plugs in which the side wall is completely covered by the integral conductive plug and the upper surface and the lower surface are covered by the uppermost wiring 960 and the intermediate wiring 940 in the upper integrated conductive plug 950. Body 94
5I are formed. An array of upper island insulators 945I as shown is formed as a preferred example.

The number and / or size of the upper island-shaped insulator 945I depends on the upper integrated conductive plug 950 and the uppermost wiring 96.
The area where 0 contacts is 10% of the area of the uppermost wiring 960
The determination is made within the above range. By setting the contact area to 10% or more, a current equal to or more than a certain value can flow to the bonding pad portion. Preferably, the plurality of island-shaped insulators 945I, also referred to as an array of spaced-apart island-shaped insulators, reduces the width of the island-shaped insulators 945I. That is, the uppermost wiring 9
The insulating film sandwiched between the intermediate wiring 60 and the intermediate wiring 940 includes a plurality of island-shaped insulators 94 in the upper integrated conductive plug 950.
It is divided into 5I. Therefore, even if one island-shaped insulator 945I is cracked, the remaining island-shaped insulator
45I is not cracked. Generally, the uppermost wiring 960 functioning as a bonding pad is rectangular,
It has a size of μm × 100 μm. Upper island insulator 9
The spacing between 45I is preferably between about 0.3 μm and 1 μm.
0 μm. In particular, the plurality of island-shaped insulators 945I are formed such that the upper integrated conductive plug 950 is formed in a sieve shape. You.

The connection structure between the intermediate wiring 940 and the lower wiring 920 is configured the same as the connection structure between the intermediate wiring 940 and the uppermost wiring 960. That is, the intermediate wiring 940 and the lower wiring 920 are electrically connected by the lower integrated conductive plug 930 including at least one or more lower island-shaped insulators 925I.

The structure of the bonding pad described above is a three-layer wiring according to the first embodiment of the present invention. However, the structure of the bonding pad may be a two-layer wiring or a multi-layer wiring including the uppermost wiring 960 and the intermediate wiring 940.

The effect of the structure of the bonding pad according to the first embodiment of the present invention will be described with reference to the uppermost wiring 960 and the intermediate wiring 9.
A description will be given with reference to the structure for connecting 40. The structure of the bonding pad according to the present invention corresponds to the uppermost wiring (26 in FIG.
0) and the lowermost wiring (see 230 in FIG. 3) are insulated by an integrated insulating film (see 250 in FIG. 3), and the insulating film 2
A plurality of independent conductive plugs (245 in FIG. 3)
) Employs a structure completely opposite to the conventional bonding pad structure for connecting the uppermost wiring 260 and the lowermost wiring 230. That is, according to the present invention, the conductive plug 950 connecting the uppermost wiring 960 and the intermediate wiring 940 is a continuous conductive plug, and the insulating plug sandwiched between the uppermost wiring 960 and the intermediate wiring 940. Most of the film is partitioned into at least one or more island-shaped insulators 945I in the integrated conductive plug 950.

The side wall of the island-shaped insulator 945I is completely covered by the integral conductive plug 950, and the wiring 96
Since the upper and lower surfaces are covered by 0,940, the structure is extremely stable. Therefore, even if a certain mechanical stress is applied at the time of chip classification and / or wire bonding, the island-shaped insulator 945I does not crack. Further, even if a crack occurs in the island-shaped insulator 945I, the crack is not propagated to the adjacent island-shaped insulator 945I.

FIG. 12 is a plan view of a bonding pad structure according to a second embodiment of the present invention, and FIG.
2 is a perspective view of the bonding pad structure shown in FIG.
FIG. 14 is a cross-sectional view of the bonding pad structure taken along the line XIV-XIV ′ of FIG. 12, and FIG.
5 is a cross-sectional view of the bonding pad structure taken along line XV-XV ′ of FIG.

Referring to FIGS. 12 to 15, in the second embodiment, the intermediate wiring 940 'is not formed as a continuous plate, but is formed as upper and lower integrated conductive plugs 950 and 930. Includes an island-shaped insulator 935I. Therefore, the island-shaped insulator in the intermediate wiring overlaps with the island-shaped insulator in the upper and lower integrated conductive plugs 950 and 930. Preferably, the island-shaped insulator 945I in the upper integrated conductive plug 950 and the island-shaped insulator 925I in the lower integrated conductive plug 930 are connected to the island-shaped insulator 935I in the intermediate wiring 940 'to form one The island-shaped insulator I is formed. The island-shaped insulators 945I and 925I in the upper and lower integrated conductive plugs 950 and 930 and the island-shaped insulator 935I existing in the intermediate wiring 940 'are connected to each other to form one island-shaped insulator I.
Is formed, the thickness of the island-shaped insulator I is three insulators 9
The sum of the thicknesses of 25I, 935I, and 945I increases the resistance to stress.

FIG. 16 is a plan view of a bonding pad structure according to a third embodiment of the present invention. Referring to FIG. 16, in the third embodiment, a plurality of island-shaped insulators 92 are formed.
5I and 945I are zigzag arrangements, which are alternately formed.

FIG. 17 is a plan view of a bonding pad structure according to a fourth embodiment of the present invention. Referring to FIG. 17, in the fourth embodiment, island-shaped insulators 945I ′, 9
25I 'is cylindrical. Further, the island-shaped insulator can be formed in various polygonal pillar shapes such as a triangular pillar or a pentagonal pillar.

FIG. 18 is a plan view of a bonding pad structure according to a fifth embodiment of the present invention. Referring to FIG. 18, in the fifth embodiment, an integrated conductive plug 93 is provided.
0 ', 950' is the wire bonding area 9 of the uppermost wiring
The insulator 929 and 949 are formed only below the peripheral region outside the region covered by 70, and the insulators 929 and 949 are formed below the central wire bonding region 970. According to the fifth embodiment, since no plug functioning as a crack generation site is formed below the wire bonding region 970, no crack is generated in the insulators 929 and 949, and the region around the wire bonding region is not formed. The uppermost wiring 96 is formed by integrated conductive plugs 930 'and 950' formed at the bottom of
A predetermined contact area with zero is secured.

FIG. 19 is a plan view of a bonding pad structure according to a sixth embodiment of the present invention. Referring to FIG. 19, in the sixth embodiment, an integrated conductive plug 93 is formed.
0 ', 950', the island-shaped insulator 925I ',
945I 'is a strip.

Referring to FIG. 20, a method of forming the bonding pad structure (see FIG. 9) according to the first embodiment of the present invention will be described. First, a step of forming the intermediate wiring 940 and the uppermost wiring 960 will be described. Underlayers 910, 9
An intermediate wiring 940 is formed on the integrated circuit substrate 900 on which the substrates 20 and 930 are formed (Step 2000). Next, an inter-wiring insulating film 945 is formed on the intermediate wiring 940 (Step 2010). The inter-wiring insulating film 945 is formed by depositing an insulator on the intermediate wiring 940 and flattening the insulating material by an etch back and / or a chemical mechanical polishing process.

Next, the inter-wiring insulating film 945 is patterned using a mask for defining a region where the upper integrated conductive plug is to be formed (step 2020). This allows
The intermediate wiring 940 is partially exposed to form a continuous trench defining at least one or more island-shaped insulators 945I.

The plurality of island-shaped insulators 945I are preferably patterned so as to be arranged in a matrix or zigzag. The spacing between the island-shaped insulators 945I,
That is, the width of the trench is about 0.3 μm to 10 μm.
And The reason for forming the gap at 0.3 μm or more is to prevent a crack generated in one island-shaped insulator 945I from being propagated to another island-shaped insulator 945I. The reason for forming the gap at 10 μm or less is to sufficiently fill the trench between the island-shaped insulators with the conductive plug.

Next, a conductive material, for example, tungsten,
A conductive film for filling the trench is formed using copper or aluminum (step 2030). Subsequently, the conductive film filling the trench is planarized by an etch-back and / or chemical mechanical polishing process to complete the upper integrated conductive plug 950 covering the side wall of the island-shaped insulator 945I (step 2040). Upper integrated conductive plug 950
Is preferably 10% or more of the area of the uppermost wiring 960 to be formed.

As another method, first, a solid conductive film electrically connected to the lower conductive film is formed on the lower conductive film. Next, the solid conductive film is etched to form a plurality of vias that penetrate the solid conductive film and are separated from each other by a predetermined distance. Next, an insulating film is formed on the solid conductive film and in the via. Finally, the insulating film is removed from the solid conductive film by etch back and / or chemical mechanical polishing, and the insulating film remains in the via.

Continuing with the description of FIG. 20, an uppermost wiring 960 functioning as a bonding pad is formed on the upper surface of the upper integrated conductive plug 950 (step 205).
0). Next, a passivation film 980 is formed on the entire surface including the uppermost wiring 960 (Step 2060). Desirably, the passivation film 980 is formed of a film that does not allow moisture to permeate, is resistant to stress, has high step coverage, and can be formed uniformly. Subsequently, the passivation film 980 is patterned to expose the wire bonding region 970 of the uppermost wiring 960 (Step 2070).

The method for forming the lower layer of the intermediate wiring 940, that is, the lower wiring 920 and the lower integrated conductive plug 930, includes steps 2000 (wiring forming step) to step 2040 (integrated conductive plug and island-shaped insulator). Is performed before the step of forming the intermediate wiring 940 in the same manner as in the step of (formation step). It is needless to say that the structure of the bonding pad of the multilayer wiring structure can be formed by repeating the step of forming the lower layered structure.

In the case of the method of manufacturing the bonding pad structure (see FIGS. 13 and 14) according to the second embodiment, the intermediate wiring 940 ′ includes the upper and lower integrated conductive plugs 950,
930 is formed in the same form. That is, step 2
Lower island insulator 925I through 000 to 2040
After forming the lower integrated conductive plug 930 having the internal shape, the steps 2010 to 2040 are performed in the same manner, and the integrated type having the intermediate island-shaped insulator 935I partially overlapping the lower integrated conductive plug 930 is formed. Is formed. Upper integrated conductive plug 950
The step of forming the uppermost wiring 960 is performed in the same manner as in the method of the first embodiment. Preferably, the lower, middle, and upper island-shaped insulators 925I, 935I, and 945I are formed to be connected together.

The present invention will be described in more detail with reference to the following experimental examples, which do not limit the present invention. Experimental Example 1 A first sample having a bonding pad structure according to the present invention was prepared. That is, four layers of aluminum wiring are formed on a substrate, an integral tungsten plug having an island-shaped insulator separated by about 3.4 μm is formed between the wirings, and the wirings are electrically connected. Was. After a passivation film was formed on the uppermost wiring, it was patterned to expose a wire bonding region. Next, a wire was bonded by a wedge method to prepare a sample.

After completing the bonding pad structure, the wire pulling strength was measured using a wire pulling strength measuring device. First Embodiment Having a Bonding Pad Structure According to the Present Invention
The number of samples is 170. Also, a first control sample 1 having a conventional bonding pad as shown in FIG.
97 samples and 170 second control samples each having the conventional bonding pad structure as shown in FIG. 7 were prepared. The wire pulling strength was measured for the control sample by the same method.

The measurement results are shown in Table 1 below and FIG. In FIG. 21, the graph plotted with --- shows the wire pulling strength of the bonding pad (first sample) according to the present invention, and the graph plotted with-△-shows the conventional bonding pad (first control sample). -□-
The graphs plotted in each represent the wire pulling strength of another conventional bonding pad (second control sample).
The cumulative distribution (%) is a value indicating, as a percentage, the number of samples from which the wire is peeled while increasing the tensile force from 0 g weight to 10 g weight. In Table 1, the cumulative distribution is a value indicating, as a percentage, the number of samples from which the wire was separated at a pull strength of 6 g weight or less.

[0049]

[Table 1] From the results shown in Table 1 and FIG. 21, it can be seen that the pad according to the present invention has higher wire pulling strength than the conventional pad.

<Experimental Example 2> For the first sample and the first and second control samples formed in the same manner as in Experimental Example 1, the contact between the wire and the aluminum wiring functioning as a bonding pad is poor. Therefore, a pad open phenomenon in which a wire is peeled off and a wire open phenomenon in which a wiring film is peeled off during bonding were measured. Further, after measuring the pad open and the wiring open, the first sample 15
The number of cracks generated in the island-shaped insulator or the inter-wiring insulating film below the uppermost aluminum wiring was measured for eight, 140 first control samples, and 142 second control samples. The number of cracks was measured using a scanning electron microscope after removing the passivation film and the uppermost aluminum wiring of each sample using an appropriate etchant. The results are shown in Table 2 below and FIG.

[0051]

[Table 2]

Referring to Table 2 and FIG. 22, the first control sample and the second control sample using the conventional pad structure had many cracks, while the first sample using the pad structure according to the present invention. Did not crack at all. Further, since no crack was generated, no wiring open phenomenon was observed in the first sample, and the frequency of the pad open phenomenon was significantly reduced as compared with the conventional pad structure.

According to the bonding pad structure of the present invention, since the uppermost wiring and the wiring below the uppermost wiring are connected by the continuous conductive plug, a contact area of a predetermined size or more can be secured. Therefore, a sufficient amount of current can be transmitted into the bonding pad structure.

The insulating film between the uppermost wiring and the lower wiring is formed from an island-shaped insulator confined in an integrated conductive plug. For this reason, the occurrence of cracks in the insulator due to physical stress applied when the probe pins are placed for chip classification or when the wires are bonded is reduced. In addition, since the insulator is formed in an island shape, the propagation of cracks to other insulators around the insulator is prevented.

Referring to FIGS. 8-11, in various embodiments according to the present invention, a plurality of island-shaped insulators 945 are provided.
I are arranged in a row, and the upper integrated conductive plug 950 has a sieve pattern. This sieve arrangement of the upper integrated conductive plug 950 reduces the possibility that the unstable upper integrated conductive plug 950 may shift even if there is stress between the upper integrated conductive plug 950 and the island-shaped insulator 945I. Lower. Therefore, cracks do not occur in the island-shaped insulator 945I even under a stress equal to or more than a predetermined value. Alternatively, even if a crack occurs, the crack does not propagate to another island-shaped insulator 945I.

The distance D1 between the island-shaped insulators 945I shown in FIG. 8 is determined in consideration of the propagation of cracks to other island-shaped insulators 945I and the manufacturing process conditions. That is, the distance D1 between the island-shaped insulators 945I is one island-shaped insulator 945I.
Must be large enough to prevent the cracks generated in the above from being propagated to other island-shaped insulators 945I. The island-shaped insulator 94
5I is formed first, a conductive material such as tungsten is formed between and above the conductive material, and the conductive material is planarized to form the upper integrated conductive plug 950. Island-shaped insulator 945I such that body 945I is completely surrounded by the conductive material.
It is desirable that the maximum distance between them is less than twice the thickness of the conductive material formed during the manufacturing process.

It is desirable that the distance D1 between the upper island-shaped insulators 945I is about 0.3 μm to 10 μm.
In an embodiment according to the present invention, the conductive material used to form the upper integrated conductive plug 950 has a thickness of about 0.4 μm to 1 μm.
It is desirable that the interval between 45I is about 0.3 μm to 2 μm. Generally, the uppermost wiring 960 functions as a bonding pad, and has a square shape of about 100 μm × 100.
It is a size of μm.

FIGS. 23 to 26 are plan views showing an array of non-aligned island-shaped insulators separated by a predetermined distance according to still another embodiment of the present invention. In the embodiment shown in FIGS. 23 and 24, the horizontal array of island insulators is misaligned or offset from one another. For this reason, only two apexes of the island-shaped insulator are adjacent to each other. By reducing the number of vertices or edges of adjacent island-shaped insulators, the amount of light diffracted during the photolithography process can be reduced.

In another embodiment according to the present invention, the vertical array of island insulators may be misaligned or offset from one another. Further, the island-shaped insulators in both the horizontal and vertical arrangements may be misaligned. Adjacent horizontal and / or vertical arrays are offset from each other by, for example, a half distance. Every other horizontal and / or vertical array is aligned, and adjacent horizontal and / or vertical arrays are misaligned or offset by half a distance between them. Of course, other intervals could be used.

As still another embodiment according to the present invention,
In some cases, the edges of the island-shaped insulator are not aligned as shown in FIG. 25, for example. As shown in FIG. 25, adjacent edges 2501 to 2506 of the non-aligned arrangement have non-aligned adjacent edges. The non-aligned edges 2501-2506 can further reduce the amount of light diffracted during the photographic etching process. Vertical edges may be misaligned.

As shown in FIG. 26, there may be cases where both the horizontal and vertical edges 2601 to 2609 are not aligned with each other. In particular, the lateral edges 2601-2605 of the non-aligned array are non-aligned with each other, and the vertical edges 2606-2609 of the non-aligned array are also non-aligned with each other. Edges that are misaligned in both the horizontal and vertical directions can further reduce the amount of light diffracted during the photoetching process.

Unlike the embodiment according to FIGS. 25 and 26 of the present invention, the horizontal and vertical arrangement of the island insulators described as an example in FIG. 8 are aligned. In such an aligned array, the four vertices of the island insulator are adjacent to each other. Therefore, in the photo-etching process, the diffraction generated at each vertex of the island-shaped insulator is overlapped, and the pattern portion corresponding to the vertex is rounded to change the critical value of the island-shaped insulator. Therefore, the thickness of the conductive film surrounding the island-shaped insulator needs to be large in order to completely surround the island-shaped insulator with the conductive film. In short, in the arrangement of FIG. 8, the four vertices are adjacent to each other, causing more diffraction, which creates ambiguous edges.

The upper island insulator 945I and the lower island insulator 925I may be non-aligned with each other. For example, the upper island insulators 945I are arranged in a non-aligned manner as shown in FIG. 23, and the lower island insulators 925I are arranged in an aligned manner as shown in FIG.

Referring again to FIG. 24, when the probe pins of the tester are placed laterally on the wire bonding area 970, the force applied by the probe pins of the tester applies to the lower and upper integrated conductive plugs 930 and 950. Along the upper and lower island insulators 945I, 9
Blocked by 25I. Therefore, the resistance of the probe pin to the force (ie, the shear force) is, for example, as shown in FIG.
As compared with the resistance of the aligned array shown in FIG. Desirably, the distance D2 between the island-shaped insulators is sufficiently large that a crack generated in one island-shaped insulator cannot propagate to another island-shaped insulator. The maximum spacing between the island-shaped insulators is preferably less than twice the thickness of the conductive material for forming the lower and upper integrated conductive plugs.

In this embodiment, the solid intermediate wiring 94
0 can be formed in a plate shape as shown in FIG.
As shown in (1), an island-shaped insulator can be formed inside. Therefore, the solid intermediate wiring 940 is overlapped with the upper and lower integrated conductive plugs 950 and 930, and in the case of the solid intermediate wiring 940 'of FIG. 14, it coincides with the upper and lower integrated conductive plugs 950 and 930.

As still another embodiment according to the present invention,
The bonding pad may include a metal bumper layer 2700 as shown in FIG. The metal bumper layer 2700 includes a conductive plug 2750 surrounded by an insulating material 2745.
It is on the upper wiring 2760 formed thereon. The upper bonding pad layer 2705 is formed on the metal bumper layer 2700. The upper bonding pad layer 2705 is directly above the metal bumper layer 2700.

At the time of manufacture, a test probe is used to test the upper bonding pad layer 2705 so that portions of the integrated circuit can be tested.
Contact repeatedly. Then, the wire is, for example, as shown in FIG.
As shown in FIG.
Bonding. The metal bumper layer 2700 reduces the likelihood that repeated contact of the test probe will reduce the mechanical coupling between the upper conductive plug 2750 and the upper interconnect 2760. Therefore, this embodiment can improve the reliability of the integrated circuit by reducing the possibility that the upper wiring 2760 may be peeled off from the upper conductive plug 2750 as a result of repeated contact with the test probe.

In the conventional bonding pad structure,
The inspection probe cuts into the upper wiring so that the upper conductive plug and the insulating material are exposed. Therefore, the solder used to bond the wires to the bonding pads comes into contact with the exposed insulating material that does not provide sufficient bonding strength, and the upper wiring is stripped from the upper conductive plug.

The bonding pad structure according to the present invention
It can be manufactured by forming the lower wiring 2740 on the first insulating film 2710. The lower wiring 2740 may be a metal such as aluminum or copper. Of course, other metals can be used. The lower wiring 2740 is patterned, and a second insulating film 2745 such as an oxide film is formed thereon. The second insulating film 2745 is patterned to form a via therein. The upper conductive plug 2750 is formed in the via using an etch-back process or a chemical mechanical polishing (CMP). Upper conductive plug 2750
Are tungsten (W), aluminum (Al), copper (C
u) and the like. Of course, other conductive materials can be used. A barrier layer (not shown) such as Ti or TiN may be deposited between the lower wiring 2740 and the second insulating layer 2745.

The second wiring 2760 is formed on the second insulating film 2745 and the upper conductive plug 2750. The metal bumper layer 2700 is formed on the second wiring 2760 using an etch back process as shown in FIG. 27 or a chemical mechanical polishing (CMP) as shown in FIG. Metal bumper layer 2700 may be as thick as 400 °. The metal bumper layer 2700 can be formed simultaneously with the plug in the internal region of the integrated circuit. Upper bonding pad layer 2
705 may be formed on the metal bumper layer 2700 to a thickness of about 8,000 to 10,000 degrees. The combined thickness of the metal bumper layer 2700 and the upper bonding pad layer 2705 is in the range of about 12,000 to 14,000. As shown in FIG. 28, the metal bumper layer 270
The thickness of the 0 and upper bonding pad layers 2705 can be adjusted to compensate for an etch-back process or chemical mechanical polishing (CMP).

The metal bumper layer 2700 contains tungsten. Of course, other metals can be used. Metal bumper layer 2
700 also corresponds to FIGS. 8 to 22 and FIGS.
6 may be formed as a bonding pad structure including an island-shaped insulator and an integrated conductive plug separated by a predetermined distance according to the present invention described with reference to FIG.

FIG. 29 shows an island-shaped insulator 290 according to the present invention.
FIG. 5 is a cross-sectional view illustrating an embodiment of a bonding pad structure having a metal bumper layer 2900 with embedded 5. As shown in FIG. 29, the island-shaped insulator 2905 is located in the metal bumper layer 2900 and located on the outer edge side.
Therefore, the inner region of metal bumper layer 2900 has fewer island-shaped insulators 2905 than island-shaped insulators 2905 located on the outer edge side. In one embodiment, there is no island insulator 2905 in the interior region of the metal bumper layer 2900. Therefore, embodiments according to the present invention are less sensitive to stress applied to the interior regions of the metal bumper layer 2900, and there is little likelihood of loosening the bond.

FIG. 30 shows a metal bumper layer 30 according to the present invention.
FIG. 9 is a cross-sectional view illustrating another embodiment of a bonding pad structure having a 00. As shown in FIG.
The conductive film 3010 and the upper conductive plug 3020 are formed using a damascene process. Also, the metal bumper layer 30
00 and the upper bonding pad layer 3005
It is formed of a single layer having a thickness in the range of about 00-14,000.

[0074]

As described above, according to the bonding pad structure of the present invention, the uppermost wiring and the wiring below the uppermost wiring are connected by a continuous conductive plug, so that a contact having a predetermined size or more is formed. The area can be secured. Therefore, a sufficient amount of current can be transmitted into the bonding pad structure.

The insulating film between the uppermost wiring and the lower wiring is formed of an island-shaped insulator confined in an integrated conductive plug. Accordingly, cracks are less likely to occur in the insulator due to the physical stress applied when the probe pins are placed for chip sorting or when the wires are bonded. In addition, since the insulator is formed in an island shape, the propagation of a crack to other surrounding insulators is also prevented.

In one specific example, the upper integrated conductive plug has a plurality of island-shaped insulators arranged in a line and is in the form of a sieve. Therefore, even if there is a stress between the upper integrated conductive plug and the island-shaped insulator, the sieve arrangement of the upper integrated conductive plug reduces the possibility of the unstable upper integrated conductive plug coming off. Therefore, cracks do not occur in the island-shaped insulator even under a stress equal to or more than a predetermined value. Alternatively, even if a crack occurs, the crack does not propagate to other island-shaped insulators.

On the other hand, the island-shaped insulators in the horizontal and / or vertical arrangement are, in one embodiment, non-aligned or offset with respect to each other. Are adjacent to each other. Accordingly, the amount of light diffracted during the photolithography process can be reduced by reducing the number of apexes or edges of the adjacent island-shaped insulators.

Although the bonding pad may include a metal bumper layer, the metal bumper layer reduces the reduction in mechanical coupling between the upper conductive plug and the upper wiring due to repeated contact of the test probe. Thus, the present invention can improve the reliability of the integrated circuit by reducing the possibility that the upper wiring peels off from the upper conductive plug as a result of repeated contact by the test probe.

Further, the present invention can be a bonding pad structure having a metal bumper layer having an island-shaped insulator therein. However, the bonding pad structure having a metal bumper layer having an island-shaped insulator therein is formed of a metal bumper layer. It is less sensitive to stresses applied to the interior area, so there is little likelihood of loosening of the bond.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of an integrated circuit bonded to a lead frame.

FIG. 2 is an enlarged plan view of the conventional bonding pad structure shown in FIG.

FIG. 3 is a perspective view of the bonding pad structure shown in FIG. 2;

FIG. 4 is a cross-sectional view of the bonding pad structure taken along the line IV-IV ′ of FIG. 2;

FIG. 5 is a cross-sectional view of the bonding pad structure taken along line VV ′ of FIG. 2;

FIG. 6 is a plan view of another conventional bonding pad structure.

7 is a cross-sectional view of the bonding pad structure taken along the line VII-VII 'of FIG.

FIG. 8 is a plan view of a bonding pad structure according to the first embodiment of the present invention.

FIG. 9 is a perspective view of the bonding pad structure shown in FIG. 8;

FIG. 10 is a sectional view of the bonding pad structure taken along line XX ′ of FIG. 8;

11 is a cross-sectional view of the bonding pad structure taken along the line XI-XI 'of FIG.

FIG. 12 is a plan view of a bonding pad structure according to a second embodiment of the present invention.

13 is a perspective view of the bonding pad structure shown in FIG.

14 is a cross-sectional view of the bonding pad structure taken along the line XIV-XIV ′ of FIG.

15 is a cross-sectional view of the bonding pad structure taken along the line XV-XV 'of FIG.

FIG. 16 is a plan view of a bonding pad structure according to a third embodiment of the present invention.

FIG. 17 is a plan view of a bonding pad structure according to a fourth embodiment of the present invention.

FIG. 18 is a plan view of a bonding pad structure according to a fifth embodiment of the present invention.

FIG. 19 is a plan view of a bonding pad structure according to a sixth embodiment of the present invention.

FIG. 20 is a block diagram illustrating a method for manufacturing a bonding pad structure according to the present invention.

FIG. 21 is a characteristic diagram showing the pulling strength of a wire bonded to a bonding pad structure according to the present invention in comparison with a conventional bonding pad.

FIG. 22 is a characteristic diagram showing pad open and wire open in a bonding pad structure according to the present invention, as compared with a conventional bonding pad structure.

FIG. 23 is a plan view illustrating an embodiment of a bonding pad structure including an array of non-aligned island-shaped insulators separated by a predetermined distance according to the present invention.

FIG. 24 is a plan view illustrating an embodiment of a bonding pad structure including an array of non-aligned island-shaped insulators separated by a predetermined distance according to the present invention.

FIG. 25 is a plan view illustrating an embodiment of a bonding pad structure including an array of non-aligned island-shaped insulators separated by a predetermined distance according to the present invention.

FIG. 26 is a plan view illustrating an embodiment of a bonding pad structure including an array of non-aligned island-shaped insulators separated by a predetermined distance according to the present invention.

FIG. 27 is a cross-sectional view illustrating an embodiment of a bonding pad structure including a metal bumper layer according to the present invention.

FIG. 28 is a cross-sectional view illustrating an embodiment of a bonding pad structure including a metal bumper layer according to the present invention.

FIG. 29 is a cross-sectional view illustrating an embodiment of a bonding pad structure including a metal bumper layer according to the present invention.

FIG. 30 is a cross-sectional view illustrating an embodiment of a bonding pad structure including a metal bumper layer according to the present invention.

[Explanation of symbols]

 920 Lower wiring 930 Lower integrated conductive plug 940 Intermediate wiring 950 Upper integrated conductive plug 960 Uppermost wiring 925I Lower island insulator 945I Upper island insulator 925,945 Interlayer insulating film 970 Wire bonding area

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Sun Kyo Mutsumi 870-24, Haeok-dong 2-dong, Gangseo-gu, Seoul, Republic of Korea Vision Bler B01 (72) Inventor Ding Takezhen Gonggi-eup, Gongki-do, Republic of Korea 107-1102, Tae-ri, Aooka Apartment 449, Building 900 (72) Inventor Wang Zhen Jong, Apartment 517, 402, Sukong-dong, Paldal-gu, Suwon-si, Gyeonggi-do, Republic of Korea No. 114, Building 608, Apartment 114, Umedan-dong, Paldal-gu, Seoul (72) Inventor Shen Jong-song Buksan Apartment 106, Building 507, No. 99, Suyeong-eup, Suwon-eup, Yongin-si, Gyeonggi-do, Republic of Korea 202, Jeong-dong, Bundang-gu, Seongnam-si, Gyeonggi-do, Republic of Korea Over preparative 104 houses 1002 No. F term (Reference) 5F033 HH08 HH19 JJ08 JJ11 JJ19 KK08 MM01 MM05 NN33 NN38 QQ08 QQ09 QQ31 QQ37 QQ48 VV07 WW02 XX17 XX19 5F044 EE06 EE11 EE12

Claims (25)

[Claims] A first conductive film and a second conductive film separated by a predetermined distance;
A conductive film, and a continuous first conductive film present between the first conductive film and the second conductive film separated by the predetermined distance and electrically connected to the first conductive film and the second conductive film separated by the predetermined distance; A third conductive film, the third conductive film being present in the continuous third conductive film,
An array of non-aligned and spaced apart island-shaped insulators extending through the conductive film and having sidewalls covered by the continuous third conductive film. Bonding pads for. 2. The bonding pad of claim 1, wherein the array includes a non-aligned, horizontal array of island-shaped insulators separated by a predetermined distance. 3. The arrangement of claim 2, wherein the arrangement includes a non-aligned, horizontal arrangement of island-shaped insulators separated by a predetermined distance and a non-aligned, vertical arrangement of island-shaped insulators, separated by a predetermined distance. A bonding pad for an integrated circuit according to claim 1. 4. An array of non-aligned and island-shaped insulators separated by a predetermined distance includes: a first island-shaped insulator having a first edge in a first direction; a first island-shaped insulator in the first direction. The bonding for an integrated circuit according to claim 1, including a second island-like insulator adjacent to the insulator and having a first edge and a second edge in a first direction misaligned. pad. 5. The array of non-aligned and island-shaped insulators separated by a predetermined distance is a first array of non-aligned and island-shaped insulators separated by a predetermined distance. A continuous fourth conductive film present between the continuous third conductive film and the second conductive film and electrically connected to the continuous third conductive film and the second conductive film; The continuous fourth conductive film exists in the continuous fourth conductive film.
A second array of island-shaped insulators extending a predetermined distance apart and extending through the conductive film and having side walls covered by the continuous fourth conductive film; 2. The integrated circuit according to claim 1, wherein a second array of insulators is non-aligned with the first array of island-shaped insulators spaced apart by a predetermined distance. Bonding pad. 6. The method of claim 1, further comprising a metal bumper layer on the first conductive film, and an upper bonding pad layer on the metal bumper layer formed for bonding with a wire. Bonding pads for integrated circuits. 7. The bonding pad according to claim 6, wherein the metal bumper layer includes tungsten. 8. The bonding pad of claim 6, wherein the metal bumper layer has a thickness of about 4,000 degrees. 9. The metal bumper layer and the upper bonding pad layer may have a thickness of about 12,000 to 14,000.
7. The bonding pad for an integrated circuit according to claim 6, wherein the bonding pad is a single layer having a thickness in the range of Å. 10. The method of claim 6, wherein the upper bonding pad layer is directly above the metal bumper layer.
3. A bonding pad for an integrated circuit according to claim 1. 11. The bonding pad according to claim 6, wherein the metal bumper layer includes an island-shaped insulator located on an outer edge side of the metal bumper layer. 12. The bonding pad for an integrated circuit according to claim 11, wherein there is no island-shaped insulator in an inner region of the metal bumper layer. 13. A conductive film including an insulating portion inside, a metal bumper layer on the conductive film and the insulating portion inside the conductive film, and an upper bonding pad on the metal bumper layer formed for bonding to a wire. And a bonding pad for an integrated circuit. 14. The bonding pad according to claim 13, wherein the metal bumper layer includes tungsten. 15. The semiconductor device according to claim 1, wherein the upper bonding pad layer is immediately above the metal bumper layer.
A bonding pad for an integrated circuit according to claim 3. 16. The bonding pad according to claim 13, wherein the metal bumper layer includes an island-shaped insulator located on an outer edge side of the metal bumper layer. 17. The bonding pad according to claim 16, wherein the metal bumper layer has no island-shaped insulator in an inner region of the metal bumper layer. 18. The bonding pad according to claim 13, wherein the metal bumper layer includes a solid metal film. 19. The first conductive film and the second conductive film separated by a predetermined distance, and the first conductive film present between the first conductive film and the second conductive film separated by the predetermined distance and separated by the predetermined distance. A continuous third conductive film electrically connected to the film and the second conductive film; and a zigzag arrangement in the continuous third conductive film to penetrate the continuous third conductive film. And an array of spaced apart island-shaped insulators, the sidewalls of which are covered by the continuous third conductive film. 20. A step of forming a lower conductive film on an integrated circuit substrate; and forming a continuous conductive film on the lower conductive film so as to be electrically connected to the lower conductive film. The continuous conductive film includes an array of non-aligned, spaced-apart island-shaped insulators therein, the array of island-shaped insulators extending through the continuous conductive film, and Covering a sidewall of an insulator with the continuous conductive film; and forming an upper conductive film on the continuous conductive film, the conductive film being electrically connected to the continuous conductive film. A method of manufacturing a bonding pad for an integrated circuit. 21. The method of claim 21, wherein forming the continuous conductive layer comprises forming a continuous conductive layer including a horizontal array of non-aligned, spaced-apart island-shaped insulators. A method for manufacturing a bonding pad for an integrated circuit according to claim 20. 22. The step of forming the continuous conductive layer includes a horizontal arrangement of non-aligned island-shaped insulators spaced apart by a predetermined distance and a vertical alignment of non-aligned island-shaped insulators spaced by a predetermined distance. The method of claim 20, further comprising forming a continuous conductive film. 23. The step of forming the continuous conductive film, comprising: forming a first island-shaped insulator having a first edge in a first direction in the continuous conductive film; A second edge in a first direction adjacent to the first island-shaped insulator and non-aligned with the first edge.
Forming an island-shaped insulator in the continuous conductive film. 21. The method of claim 20, further comprising the steps of: 24. The array of non-aligned, spaced-apart, island-shaped insulators is a first array of non-aligned, spaced-apart, island-shaped insulators. Forming a continuous fourth conductive film between the film and the lower conductive film and electrically connected to the continuous conductive film and the lower conductive film; Penetrating the continuous fourth conductive film into the continuous fourth conductive film, a second array of island-like insulators separated by a predetermined distance that is not aligned with the first array of formed island-shaped insulators. 21. The method of claim 20, further comprising forming the second conductive layer so as to cover the sidewall by the fourth conductive layer. 25. Every other horizontal array is aligned,
The bonding pad for an integrated circuit according to claim 1, wherein adjacent horizontal arrays are misaligned by a half distance.