JPH06260529A - Semiconductor device - Google Patents

Abstract

(57) [Summary] [Structure] A plurality of bonding pads 6 _{1 to} 6 ₄ of the same shape arranged vertically side by side and interlayer insulating films 3 ₁ to ₃ 3 existing between the plurality of bonding pads 6 _{1 to} 6 _4. Form a multi-layer wiring structure, and the plurality of bonding pads 6 _{1 to} 6 ₄ are mutually connected via through holes 10 ₁ to 10 ₃ opened in a part of the interlayer insulating films 3 ₁ to ₃ 3 existing between them. It is characterized in that it is electrically connected and a part of the plurality of bonding pads 6 _{1 to} 6 ₄ is connected to an aluminum wiring layer laminated at the same height. [Effect] There is an effect that it can be directly connected to an arbitrary aluminum wiring layer among a plurality of aluminum wiring layers, and the size can be reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device having a multilayer wiring structure including a metal wiring layer and an interlayer insulating film.

[0002]

2. Description of the Related Art FIG. 3 shows a conventional semiconductor device.
(a) is a plan view and (b) is a side sectional view. In the figure, 1
An insulating film, 2 ₁ aluminum wiring layer as a metal wiring layer formed on the insulating film 1, 3 ₁ interlayer insulating film formed on the insulating film 1 and the aluminum wiring layer 2 _1, 4 ₁ interlayer insulating is a through hole which is opened in the film 3 _1. Similarly, 2 ₂ aluminum wiring layer formed on the interlayer insulating film 3 _1, 3 ₂ aluminum wiring layer 2 ₂ and the interlayer insulating film 3 ₁ on the formed interlayer insulating film, 4
Reference numeral ₂ is a through hole formed in the interlayer insulating film 3 ₂ . Aluminum wiring layer 2 ₂ is formed satisfies the through-hole 4 in ₁ conducts the aluminum wiring layer 2 _1. Further, 2 ₃ is an aluminum wiring layer formed on the interlayer insulating film 3 ₂ , and 5 is a passivation film formed on the aluminum wiring layer 2 ₃ and the interlayer insulating film 3 ₂ . Aluminum wiring layer 2 ₃ is conductive is formed satisfies the through-hole 4 in ₂ and aluminum interconnection layer 2 _2. Reference numeral 6 is a bonding pad integrated with the aluminum wiring layer 2 ₃ . Since this semiconductor device has many aluminum wiring layers, it is called a multilayer wiring structure, and in this case, it is also called a three-layer wiring structure.

In the semiconductor device having the above structure, the aluminum wiring layers 2 ₁ , 2 ₂
Electrical connection to is made via through holes 4 ₁ , 4 ₂ . However, since a certain amount of space is required between the through holes 4 ₁ and 4 ₂ and between the through hole 4 ₂ and the bonding pad 6, the bonding pad 6 and the aluminum wiring layers 2 ₁ and 2 ₂ A certain area is required for the connection with the semiconductor device, which may hinder the miniaturization of the semiconductor device. Especially, since the connection to the lowermost aluminum wiring layer 2 ₁ is made through the two through holes 4 ₁ and 4 ₂ , a large area is required. Further, in the case of the multilayer wiring structure having more aluminum wiring layers than the three layers in the case of FIG. 3, a very large area is required for the connection between the lowermost aluminum wiring layer and the bonding pad. It

For this reason, a conventionally taken measure is to make the structure around the bonding pad as shown in FIGS. 4 (a) and 4 (b). These structures are formed as follows. That is, first, the bonding pad 6 is formed on the insulating film 1.
₁ to form through hole 7 on bonding pad 6 _1.
An interlayer insulating film 3 ₁ having ₁ to form a bonding pad 6 ₂ covers the through holes 7 _1, an interlayer insulating film 3 ₂ having a through-hole 7 ₂ on the bonding pad 6 ₂
Then, the bonding pad 6 ₃ is formed so as to cover the through hole 7 ₂ , and further the passivation film 5 having the through hole 7 ₃ is formed on the bonding pad 6 ₃ . The bonding pads 6 _{1 to} 6 ₃ have almost the same size.

By forming the bonding pad 6 ₂ integrally with the aluminum wiring layer 2 ₂ as shown in FIG. 4A, the aluminum wiring layer 2 ₂ and the bonding pad 6 ₂ can be electrically connected, and By forming the bonding pad 6 ₁ integrally with the aluminum wiring layer 2 ₁ as shown in FIG. 4B, the lowermost aluminum wiring layer 2 ₁ and the bonding pad 6 ₁ can be electrically connected. Similarly, the uppermost aluminum wiring layer and the bonding pad 6 ₃ can be electrically connected. In the semiconductor device of the structure shown in FIG. 4, in yet assembling process, a gold wire or aluminum wire is wire bonded to the bonding pad 6 _3.

[0006]

Since the conventional semiconductor device is constructed as described above, the position where the crimp ball 8 which is the end of the wire is crimped at the time of wire bonding is bonded as shown in FIG. If it shifts from the center of the pad 6 ₃ toward the end, the bonding pad 6 ₃
Since the flatness of the upper surface is poor and the pressure-bonding ball 8 hits one side and the ultrasonic impact at the time of pressure-bonding is concentrated on a part of the bonding pad 6 ₃ and its periphery, the interlayer insulating films 3 ₁ , 3 ₂ and the passivation film 5 are not affected. A crack 9 may occur. In this case, the pressure bonding ball 8 may come off from the bonding pad 6 ₃ and the connection between the bonding pads 6 _{1 to} 63 ₃ and the aluminum wiring layer 2 ₁ may be broken, so that the reliability of the semiconductor device is reduced. There was a problem of decrease.

The present invention has been made in order to solve the above problems, and is provided with a bonding pad that can be directly connected to an arbitrary aluminum wiring layer among a plurality of aluminum wiring layers, and has a small size. The purpose is to obtain a highly reliable semiconductor device.

[0008]

In a semiconductor device according to a first aspect of the present invention, a plurality of bonding pads of the same shape arranged vertically are provided and an interlayer insulating film existing between the plurality of bonding pads is multi-layered. It has a wiring structure, and a plurality of bonding pads are electrically connected to each other through a through hole opened in a part of the interlayer insulating film existing between them, and a part of the plurality of bonding pads have the same height. Is connected to the metal wiring layer laminated on.

A semiconductor device according to claim 2 of the present invention is
A through hole opened in the interlayer insulating film laminated on each bonding pad and a through hole opened in the interlayer insulating film laminated below are arranged at positions not overlapping vertically.

[0010]

In the semiconductor device according to the first aspect of the present invention, the bonding pads are connected to each other through the through holes, and each bonding pad is connected to the metal wiring layer. As a result, the area required for connecting the bonding pad and the metal wiring layer can be reduced, and the semiconductor device can be miniaturized.

In the semiconductor device according to the second aspect of the present invention, by shifting the positions of the adjacent through holes from each other, the portions of the through holes having poor flatness overlap and the flatness of the uppermost bonding pad is superposed. Since it is possible to prevent deterioration of the pressure-bonded balls and to prevent uneven contact of the pressure-bonded balls, it is possible to obtain a bonding pad that is strong against an impact during wire bonding. further,
If the positions of the through holes are vertically overlapped, the impact during wire bonding will be concentrated on this portion, but if the positions of the adjacent through holes are displaced, the impact can be dispersed.

[0012]

EXAMPLES Example 1. The first embodiment is an embodiment according to claims 1 and 2 of the present invention. 1A is a plan view of the bonding pad, and FIG. 1B is a sectional view of a main part of the bonding pad along the line AA shown in FIG. 1A, which is the same as or equivalent to the conventional semiconductor device shown in FIG. Are denoted by the same reference numerals, and description thereof will be omitted. 1, 3 ₃ interlayer insulating film formed on the bonding pads 6 _3, 6 ₄ bonding pad formed on the interlayer insulating film 3 _3, 10 ₁ -
Numeral 10 ₃ is a band-shaped through hole having a width of 5 μm or less, which is formed in the interlayer insulating films 3 _{1 to} 3 ₃ and has a square shape along the outer periphery of the bonding pads 6 _{1 to} 6 ₄ .

To form the bonding pad shown in FIG. 1, first, the bonding pad 6 ₁ is formed on the insulating film 1, and the interlayer insulating film 3 ₁ having the through hole 10 ₁ formed therein is formed.
Is formed on the bonding pad 6 ₁ , and the through hole 10 ₁ is filled on the interlayer insulating film 3 ₁ to form the bonding pad 6 ₂ . Similarly, the bonding pads 6 ₃ , 6 ₄
To form. The bonding pads 6 _{1 to} 6 ₄ have the same shape and are electrically connected to each other at the positions of the through holes 10 ₁ to 10 ₃ . Each bonding pad ₆₁ through ₄ are simultaneously formed in the step of forming each aluminum wiring layer of the multilayer wiring structure (not shown), this time, the bonding pad ₆₁ through ₄ in the step of forming any of the aluminum wiring layer of aluminum by forming the wiring layer as an integral, bonding pads 6 ₁
6 ₄ is electrically connected to an arbitrary aluminum wiring layer.

As described above, the bonding pads 6 _{1 to} 6 ₄
Are connected to each other through through holes 10 ₁ to 10 ₃ and the bonding pads 6 _{1 to} 6 ₄ are integrally formed with an arbitrary aluminum wiring layer, so that the arbitrary aluminum wiring layer is directly connected to the bonding pad. it can, bonding pads ₆₁ through ₄ and it is possible to reduce the area required for connection of the aluminum wiring layer, it is possible to reduce the size of the semiconductor device thus.

Further, a through hole 10 ₂ opened in the interlayer insulating film 3 ₂ laminated on the bonding pad 6 ₂ ,
The through holes 10 ₁ formed in the underlying interlayer insulating film 3 ₁ are arranged at positions that do not vertically overlap.
That is, the through hole 10 ₁ is arranged outside the through hole 10 ₂ (see FIG. 1A). The through holes 10 ₂ and 10 ₃ above and below the bonding pad 6 ₃ have the same relationship.

Generally, when a through hole is formed, the flatness of the layer thereabove becomes poor. However, by shifting the positions of the adjacent through holes 10 ₁ to 10 ₃ from each other,
It is possible to prevent the flatness of the uppermost bonding pad 6 _{4 from} being deteriorated in a superposed manner due to overlapping of portions having poor flatness, and it is possible to prevent uneven contact of the crimping ball, so that it is possible to prevent impact during wire bonding. Strong bonding pads 6 _{1 to} 6 ₄ can be obtained. Furthermore, if the positions of the adjacent through holes 10 ₁ to 10 ₃ are vertically overlapped, the impact during wire bonding will be concentrated on this portion, but the positions of the adjacent through holes 10 ₁ to 10 ₃ are shifted. In the case of impact, the impact can be dispersed. Therefore, the bonding pads 10 ₁ to 10 ₃ are strong against impact during wire bonding, and the reliability of the semiconductor device can be improved.

Example 2. The second embodiment is an embodiment according to claims 1 and 2 of the present invention. In the first embodiment, the through holes 10 ₁ and 10 ₃ are arranged outside the bonding pads 6 _{1 to} 6 ₄ with respect to the through hole 10 ₂ so that the positions of the adjacent through holes 10 ₁ to 10 ₃ are displaced from each other. However, in the second embodiment, the positions of the through holes are shifted by adopting another structure.

FIG. 2 is a plan view of a bonding pad according to the second embodiment of the present invention. This bonding pad also has a four-layer wiring structure as shown in FIG. 1B, and in FIG. 2, 11 ₁ is a through hole for connecting the bonding pad of the lowermost layer and the second layer which is the upper layer thereof, 11 ₂
A through hole for connecting the bonding pads of the second and third layers, 11 ₃ is a through-hole connecting the third layer and the uppermost layer of the bonding pad. As shown, the through holes 11 _{1 to} 11 _{3 have} a size of 5 μm on the short side.
It is a strip shape of m or less, and they are alternately arranged on the circumference of one square. That is, the top through hole 11 ₃ is arranged at the position shown by the solid line in FIG. 2, the middle through hole 11 ₂ is arranged at the position shown by the dotted line, and the through hole 11 ₃ and the through hole 11 ₂ are The arrangement is alternating. Further, the bottom through hole 11 ₁ is arranged at the same position as the through hole 11 ₃ , and the through holes 11 ₂ and the through holes 11 ₁ are arranged alternately.

With such an alternate arrangement, the positions of vertically adjacent through holes can be shifted from each other, as in the first embodiment, the flatness of the uppermost bonding pad can be improved, and the through holes can be formed. Since it is possible to reduce the concentration of impact during wire bonding, it is possible to obtain a highly reliable semiconductor device that is resistant to impact during wire bonding pads.

In each of the above-mentioned embodiments, the four-layer wiring structure having four aluminum wiring layers is used, but the same effect can be obtained with a multi-layer wiring structure other than four layers. Further, even if a wiring material other than aluminum is used for the metal wiring layer, the same effect can be obtained.

[0021]

Since the present invention is constructed as described above, it has the following effects.

According to the semiconductor device of the first aspect of the present invention, the plurality of bonding pads of the same shape arranged vertically and the interlayer insulating film existing between the plurality of bonding pads form a multilayer wiring structure, The plurality of bonding pads are electrically connected to each other through a through hole formed in a part of the interlayer insulating film existing between them, and a part of the plurality of bonding pads are stacked at the same height. Since it is connected to the wiring layer, it can be directly connected to an arbitrary aluminum wiring layer among the plurality of aluminum wiring layers, and there is an effect that miniaturization can be achieved.

According to the semiconductor device of the second aspect of the present invention, the through hole opened in the interlayer insulating film laminated on each bonding pad and the through hole opened in the interlayer insulating film laminated below. Since and are arranged at positions where they do not vertically overlap, in addition to the effect of claim 1, there is an effect that they are resistant to impact during wire bonding and reliability is increased.

[Brief description of drawings]

1A and 1B show a bonding pad in Example 1, where FIG. 1A is a plan view and FIG. 1B is a cross-sectional view of essential parts.

FIG. 2 is a plan view of a bonding pad according to a second embodiment.

3A and 3B show an example of a bonding pad of a conventional semiconductor device, in which FIG. 3A is a plan view and FIG. 3B is a side sectional view.

4A and 4B are side sectional views showing another example of a bonding pad of a conventional semiconductor device.

5 is a side sectional view showing a state in which wire bonding is performed on the bonding pad shown in FIG.

[Explanation of symbols]

3 _{1 to} 3 ₃ Interlayer insulating film 6 _{1 to} 6 ₄ Bonding pad 10 ₁ to 10 ₃ Through hole 11 _{1 to} 11 ₃ Through hole

Claims (2)

[Claims] 1. A semiconductor device having a multilayer wiring structure having a plurality of metal wiring layers and an interlayer insulating film laminated between the metal wiring layers, wherein a plurality of bonding pads of the same shape are arranged vertically. An interlayer insulating film existing between the plurality of bonding pads forms a multilayer wiring structure, and the plurality of bonding pads electrically connect to each other through a through hole formed in a part of the interlayer insulating film existing between them. And a part of the plurality of bonding pads are connected to the metal wiring layer stacked at the same height. 2. A through hole opened in an interlayer insulating film laminated on each bonding pad and a through hole opened in an interlayer insulating film laminated below are arranged at positions not vertically overlapping each other. The semiconductor device according to claim 1, wherein: