JPH0794548A - Semiconductor device and fabrication thereof - Google Patents

Abstract

PURPOSE:To prevent fracture due to interference between a wire and the peripheral protective film at the time of wire bonding by improving the structure at the bonding pad part of a semiconductor device. CONSTITUTION:A lower insulation film 102 is deposited on a semiconductor substrate 101 and a lower thin metal film 110 is formed thereon within a bonding pad opening 120. An intermediate insulation film 103 is then deposited on the lower thin metal film 110 and the peripheral lower insulation film 102 within the bonding pad opening 120. Furthermore, an upper thin metal film 111 providing a bonding pad part is deposited on the intermediate insulation film 103 and the peripheral lower insulation film 102 while protruding upward from the upper side of the intermediate insulation film 103. Upper end of the protective insulation film 104 on the periphery of the bonding pad opening 120 is set lower than the bonding pad part. This structure prevents interference between the protective insulation film 104 and the bonding wire.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device and a method of manufacturing the same, and more particularly to a measure for preventing interference between a bonding wire and a protective film around a bonding pad.

[0002]

2. Description of the Related Art In recent years, with widespread use of electronic devices using semiconductor devices and cost reduction thereof, demands for high integration and cost reduction of semiconductor devices are increasing, and comparison of ratios in chip size Reducing the size of bonding pad, which is relatively large, is becoming an important issue.

An example of a conventional semiconductor device will be described below with reference to the drawings. FIG. 5 is a cross-sectional view of a bonding pad arranged in a conventional semiconductor device. In FIG. 5, 101 is a semiconductor substrate, 102 is a lower layer insulating film, 103 is an intermediate layer insulating film, 104 is an uppermost protective insulating film, 110 is a lower metal thin film that functions as wiring, and 111 is an upper metal layer that functions as wiring. Thin film, 120
Is a bonding pad opening formed in the protective insulating film 104. The thickness of each part in FIG. 5 is 200 nm for the lower insulating film 102, 700 nm for the upper insulating film 103,
The protective insulating film 104 is 1000 nm, and the lower metal thin film 11 is formed.
0 is 550 nm, and the upper metal thin film 111 is 850 nm. Here, the uppermost surface of the protective insulating film 104 projects above the bonding pad portion of the upper metal thin film 111, and the difference h between them is 1700 nm (1.7 μm). The width of the opening 120 is about 100 μm.

[0004]

However, in the above-described conventional structure of the bonding pad portion, there is no problem if the bonding pad opening portion 120 is sufficiently larger than the bonding wire diameter, but the bonding pad opening portion 120 has When the size is less than four times the diameter of the bonding wire, the ball at the tip of the wire becomes a protective insulating film 104.
Since it hits the uppermost part A, there is a problem that reliability is deteriorated due to breakage of the protective insulating film 104 and assembly failure occurs due to a decrease in adhesion strength between the wire and the upper metal thin film 111.

The present invention has been made in view of the above problems, and an object thereof is to provide a structure in which a bonding pad portion of an upper layer wiring is made to project above a peripheral protective film, and thereby a wire is formed. The purpose of this is to prevent interference between the wire and the surrounding protective film in the bonding step, thereby improving reliability.

[0006]

In order to achieve the above object, specifically, the means taken by the invention of claim 1 is to provide a two-layer wiring consisting of a lower metal thin film and an upper metal thin film above a semiconductor substrate, A semiconductor device having a protective insulating film for protecting the upper metal thin film and having a bonding pad opening region in a part of the protective insulating film is intended.

Then, a lower layer insulating film is provided above the semiconductor substrate and below the protective insulating film, and the lower layer metal thin film is formed on the surface of the lower layer insulating film and in a region which is in the bonding pad opening region. Form.

Further, an intermediate insulating film is provided on the surface of the lower metal thin film and the surrounding lower insulating film in the vicinity thereof and in a region which is within the bonding pad opening region, and the upper metal thin film is provided with the intermediate insulating film. The bonding pad portion is formed on the surface of the film and the lower insulating film around the film and above the intermediate insulating film to form a bonding pad portion protruding upward.

Further, the protective insulating film is formed on the surface of the upper layer metal thin film and the surrounding lower layer insulation film so as to expose the bonding pad portion of the upper layer metal thin film in the bonding pad opening region. The height of the upper end surface is lower than the bonding pad portion of the upper metal thin film.

According to a second aspect of the present invention, there is provided means for providing, above a semiconductor substrate, an ohmic metal thin film which makes ohmic contact with the semiconductor substrate, and a lower metal thin film and an upper metal thin film provided on the ohmic metal thin film. The present invention is directed to a semiconductor device having a two-layered wiring and a protective insulating film provided on the upper metal thin film, and having a bonding pad opening region in a part of the protective insulating film.

Then, the ohmic metal thin film is formed in the bonding pad opening region, and the ohmic metal thin film is formed on the surface of the ohmic metal thin film and the lower insulating film around the ohmic metal thin film, and in a region inside the bonding pad opening region. 1
An intermediate insulating film is provided, and the lower metal thin film is formed on the surface of the first intermediate insulating film and the semiconductor substrate around the first intermediate insulating film.

Further, a second intermediate layer insulating film is provided on the surface of the lower metal thin film and the semiconductor substrate around it, and the upper metal thin film is used as the second intermediate layer insulating film and the lower insulating film around it. It is formed to have a bonding pad portion protruding upward on the surface and at least above the first intermediate insulating film.

Further, the protective insulating film is formed on the surface of the upper metal thin film and the surrounding semiconductor substrate so as to expose the bonding pad portion of the upper metal thin film in the bonding pad opening region, and The upper end surface is formed at a height lower than the bonding pad portion.

According to a third aspect of the invention, in the invention of the first or second aspect, the upper metal thin film is formed so as to be electrically connected to the lower metal thin film.

According to a fourth aspect of the invention, means is provided, above the semiconductor substrate, a two-layer wiring composed of a lower metal thin film and an upper metal thin film, and a protective insulating film for protecting the upper metal thin film. The present invention is directed to a method of manufacturing a semiconductor device having a bonding pad opening region in a part of the protective insulating film.

Then, a step of forming a lower layer insulating film above the semiconductor substrate, and a step of forming the lower layer metal thin film on the surface of the protective insulating film and in a region which is in the bonding pad opening region, A step of forming an intermediate-layer insulating film on the surface of the lower-layer metal thin film and its surrounding lower-layer insulating film, and in a region that will be in the bonding pad opening region; A step of forming the upper metal thin film on the surface, depositing a protective insulating film on the surface of the upper metal thin film and the lower insulating film, and then forming the bonding opening region in the protective insulating film for protection. And a step of exposing the bonding pad portion so that the upper end of the insulating film for use is below the bonding pad portion of the upper metal thin film.

According to a fifth aspect of the present invention, above means is provided, above the semiconductor substrate, an ohmic metal thin film in ohmic contact with the semiconductor substrate, a two-layer wiring including a lower metal thin film and an upper metal thin film, and the upper metal thin film. A method for manufacturing a semiconductor device, which comprises a protective insulating film for protection and has a bonding pad opening region in a part of the protective insulating film.

Then, a step of forming an ohmic metal thin film in a region on the surface of the semiconductor substrate to be in the bonding pad opening region, and on the surface of the ohmic metal thin film and the semiconductor substrate around the ohmic metal thin film and the bonding pad opening. A step of forming a first intermediate layer insulating film in a region to be within the region, and the lower layer metal on the surface of the semiconductor substrate around the first intermediate layer insulating film and its periphery and in a region to be in the bonding pad opening region. A step of depositing a thin film, a step of depositing a second intermediate insulating film on the surface of the lower metal thin film and the semiconductor substrate around it, and a step of depositing a second intermediate insulating film on the surface of the second intermediate insulating film and around the semiconductor substrate Forming the upper metal thin film, depositing a protective insulating film on the surfaces of the upper metal thin film and the semiconductor substrate, and then forming the bonding film on the protective insulating film. And forming an opening region, a protective method upper end of the insulating film is provided and a step of exposing the bonding pad portion so as to be lower than the bonding pad portion of the upper metallic thin film.

[0019]

With the above structure or method, in the invention of claim 1 or 4, in the semiconductor device having the two-layer wiring structure,
In the bonding pad opening area of the protective insulating film,
The bonding pad portion of the upper metal thin film is provided in a shape protruding upward on the intermediate insulating film laminated on the lower metal thin film, and the bonding pad portion is higher than the upper end of the peripheral portion of the bonding pad of the protective insulating film. Since the height is high, the wires are prevented from interfering with the protective insulating film during wire bonding, and damage to the protective insulating film is prevented.

According to the second or fifth aspect of the invention, also in the semiconductor device having the ohmic metal thin film which makes ohmic contact with the semiconductor substrate and the two-layer wiring structure, the same action as that of the invention of the above-mentioned first aspect is exerted at the time of wire bonding. Interference between the wire and the protective insulating film is prevented.

According to the third aspect of the invention, since the upper metal thin film and the lower metal thin film are electrically connected to each other, it is possible to connect the elements and the like in the semiconductor substrate to the wiring through the lower metal thin film. Therefore, the step difference in the wiring structure is reduced.

[0022]

Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment 1) First, Embodiment 1 will be described with reference to FIGS. FIG. 1 is a sectional view showing a structure in the vicinity of a bonding pad portion of a semiconductor device having a two-layer metal wiring structure. In FIG. 1, 101 is a semiconductor substrate, 102 is a first-layer insulating film corresponding to the lower-layer insulating film according to the invention of claim 1 or 3, and 103 is claim 1.
Or a second equivalent to the intermediate layer insulating film according to the invention of claim 3
A layer insulating film, 104 is a protective insulating film, 110 is a lower metal thin film that functions as a lower wiring, 111 is an upper metal thin film that functions as an upper wiring, and 120 is the protective insulating film 104.
This is the bonding pad opening. The thickness of each film in FIG. 1 is 200 nm for the first insulating film 102, 700 nm for the second insulating film 103, and 100 for the protective insulating film 104.
0 nm, the lower metal thin film 110 is 550 nm, and the upper metal thin film 111 is 850 nm.

FIGS. 2A to 2E are sectional views showing the bonding pad manufacturing process of the first embodiment. In FIG. 2, reference numeral 130 is a photoresist film, and other members are shown in FIG.
It is represented by a common code.

First, as shown in FIG. 3A, a first layer insulating film 102 is deposited on the surface of a semiconductor substrate 101, and then a lower metal thin film 110 is formed on the surface of the first layer insulating film 102.
To form. Au is used as the metal, and the thickness is 550 nm. Then, after forming a resist pattern that covers only a predetermined region included in the bonding pad opening 120, the lower metal thin film 110 that is not covered with the photoresist is removed by a method such as ion milling.
The lower metal thin film 110 is formed in a predetermined region inside the bonding pad opening 120.

Next, as shown in FIG. 3B, a second metal film is formed on the surfaces of the lower metal thin film 110 and the first insulating film 102.
After depositing the layer insulating film 103, the second layer insulating film 103 other than the region covered with the photoresist is removed by a dry etching method or the like using a photoresist pattern. That is, the second layer insulating film 103 is formed in the bonding pad opening 120. Silicon nitride is used as the material forming the second layer insulating film 103, and the thickness thereof is 700 nm.

Next, as shown in FIG. 6C, an upper metal thin film 111 is deposited on the surfaces of the second layer insulating film 103 and the first layer insulating film 102, and ion milling or the like is performed using a resist pattern. As a result, the upper metal thin film 11 is formed while leaving only the second layer insulating film 103 and the surrounding portions of the first layer insulating film 102. The metal forming the upper metal thin film 111 is Au, and the thickness thereof is 850 nm. That is, the upper metal thin film 111 is used as the second layer insulating film 10
The upper side of 3 has a shape protruding upward.

Further, as shown in FIG. 3D, a protective insulating film 104 is deposited on the surfaces of the upper metal thin film 111 and the first insulating film 102. Silicon nitride is used as a material for the protective insulating film 104, and its thickness is 1000 n.
m. After that, a photoresist is applied to the entire surface, and then exposure and development are performed to form the bonding pad opening 1
A photoresist pattern 130 having openings 20 is formed.

Finally, as shown in FIG. 3E, the protective insulating film 104 is opened by a dry etching method using the photoresist pattern 130 to expose the upper metal thin film 111 of the bonding pad portion. Then, the photoresist pattern 130 is removed. At this time, the height of the protective insulating film 104 around the bonding pad from the first layer insulating film 102 was 1850 nm, and the height of the bonding pad part of the upper metal thin film 111 from the first layer insulating film 102 was 2100 nm. And the upper metal thin film 111
The bonding pad portion of is the peripheral insulating film 10 for protection
The structure is higher than 4.

Therefore, in the first embodiment, the difference h'between the bonding pad portion of the upper metal thin film 111 and the uppermost surface of the surrounding protective insulating film 104 is 250 nm (0.25 μm).
m), and the bonding pad portion is higher. That is, the lower metal thin film 110 and the first-layer insulating film 1 around it
02 and the bonding pad opening 120
The second-layer insulating film 103 is formed in the inner region, the upper-layer metal thin film 111 is formed thereon, and the upper-layer metal thin film 111 is formed.
Since the bonding pad portion has a shape protruding above the surrounding protective insulating film 104, the wire does not interfere with the protective insulating film 104 during wire bonding. Therefore, it is possible to effectively prevent damage to the protective insulating film 104 and defective bonding due to the reduction in size of the semiconductor device, and it is possible to improve reliability.

In addition, the manufacturing method of the first embodiment does not require a dedicated step for forming the bonding pad, and can be formed by using a normal multilayer wiring forming step. That is, it can be formed by the same procedure as the step of alternately providing the interlayer insulating film and the metal wiring. Therefore,
The reliability can be improved without increasing the cost.

(Embodiment 2) Next, Embodiment 2 relating to a semiconductor device having an ohmic electrode structure will be described with reference to FIGS. FIG. 3 is a sectional view in the vicinity of the bonding pad portion of the semiconductor device. In FIG.
The members with the same reference numerals as the members in the above-mentioned Embodiment 1 are
Since the constituent materials and the thickness are the same as those in the first embodiment, the description thereof will be omitted. However, in Example 2, the first-layer insulating film 102
Corresponds to the first intermediate layer insulating film referred to in the invention of claim 2 or 4, and the second layer insulating film 103 corresponds to claim 2 or 4.
Corresponds to the second intermediate-layer insulating film. Further, an ohmic electrode 112, which is an ohmic metal thin film in ohmic contact with the semiconductor substrate 101, is provided, and its thickness is 200 nm.

That is, in the second embodiment, in the case of the wiring structure having the ohmic electrode 112, the ohmic electrode 11 is used.
2 is formed on the semiconductor substrate 101 and in a region to be in the bonding pad opening 120, and the first-layer insulating film 102 is formed on the semiconductor substrate 101 and on the periphery thereof in the region in the bonding pad opening 120. And the lower metal thin film 110 and the second metal thin film 110
Layer insulating film 103, upper insulating film 111 and protective insulating film 1
04 are sequentially formed, and the bonding pad portion of the upper metal thin film 111 exposed in the bonding pad opening 120 is higher than the upper end of the surrounding protective insulating film 104.

Next, the manufacturing process of this semiconductor device will be described with reference to the sectional views of FIGS.

First, as shown in FIG. 3A, a photoresist is applied over the entire surface of a semiconductor substrate 101, a portion corresponding to a bonding pad portion is exposed and developed, and a photoresist having a pattern in which the portion is opened. The film 140 is formed. After that, a metal for the ohmic electrode 112 is deposited on the entire surface. AuGe-Ni-Au is used for this metal, and the thickness thereof is 200 nm.

Next, as shown in FIG. 3B, the photoresist film 140 is completely removed by the lift-off method.
The patterning is performed so that only the ohmic electrode 112 in a predetermined region remains. Then, the first-layer insulating film 102 is formed on the patterned ohmic electrode 112 and on the periphery thereof and only in the region within the bonding pad opening 120.

Next, as shown in FIG.
After the lower metal thin film 110 is formed on the layer insulating film 102 and the semiconductor substrate 101 in the periphery thereof and in the region to be in the bonding pad opening 120, the lower metal thin film 110 and the semiconductor substrate 101 in the periphery thereof are further formed. The second-layer insulating film 103 is formed in the region above and in the bonding pad opening 120.

Next, as shown in (d) and (e) of FIG.
2D and 2E in the first embodiment, the protective insulating film 104 having the bonding pad opening 120 is formed and the bonding pad portion of the upper metal thin film 111 is exposed.

Therefore, in the second embodiment, the uppermost surface of the protective insulating film 104 is lower than the bonding pad portion of the upper metal thin film 111, and the difference h ″ between them is 12500 nm.
(1.25 μm). That is, the second embodiment
Also in this case, the same effect as that of the above-described first embodiment can be obtained.

Although the upper metal thin film 111 and the lower metal thin film 110 are electrically connected in the first and second embodiments, the present invention is not limited to these embodiments. However, with the structure in which the upper and lower metal thin films are electrically connected, the connection with the element below can be performed through the lower metal thin film 110, and the upper metal thin film 11
It is possible to reduce the step difference as compared with the case where the connection with the element is made through 1.

[0041]

As described above, according to the invention of claim 1, as a structure of a semiconductor device having a two-layer metal wiring structure and having a bonding pad opening region in a part of a protective insulating film, bonding is performed. A lower metal thin film and an intermediate insulating film are sequentially laminated in the pad opening area, and the bonding pad portion of the upper metal thin film is projected upward in the bonding pad opening area to form a protective insulating film around the bonding pad. Since the upper end of the structure is lower than the bonding pad portion of the upper metal thin film, even when the semiconductor device is downsized, it is possible to prevent interference between the wire and the protective insulating film during wire bonding. Therefore, the reliability can be improved.

According to the invention of claim 2, as a structure of a semiconductor device having an ohmic electrode and a two-layer metal wiring structure, and having a bonding pad opening region in a part of a protective insulating film, a The ohmic electrode, the first intermediate layer insulating film, the lower metal thin film, and the second intermediate insulating film are stacked on top of each other, and the bonding pad portion of the upper metal thin film is projected upward in the bonding pad opening region to perform bonding. Since the upper end of the protective insulating film around the pad is formed so as to be lower than the bonding pad portion of the upper metal thin film, it is possible to prevent interference between the wire and the protective insulating film during wire bonding and to improve reliability. It is possible to improve.

According to the invention of claim 3, in the invention of claim 1 or 2, the upper metal thin film and the lower metal thin film are electrically connected to each other, so that a step difference in the multilayer wiring structure is reduced. be able to.

According to the invention of claim 4, as a method of manufacturing a semiconductor device having a two-layer metal wiring structure and having a bonding pad opening region in a part of a protective insulating film, a portion corresponding to the bonding pad opening region is provided. Then, the lower metal thin film and the intermediate insulating film are sequentially formed, and the bonding pad portion of the upper metal thin film is formed so as to project upward in the bonding pad opening region so that the upper end of the protective insulating film around the bonding pad is Since it is formed so as to be lower than the bonding pad portion of the upper metal thin film, it is possible to add a dedicated bonding pad forming step without additional steps.
It is possible to form a highly reliable bonding pad portion in the process of forming an ordinary two-layer metal wiring structure.

According to a fifth aspect of the present invention, there is provided a bonding pad opening region as a method of manufacturing a semiconductor device having an ohmic electrode and a two-layer metal wiring structure and having a bonding pad opening region in a part of a protective insulating film. An ohmic electrode, a first intermediate layer insulating film, a lower layer metal thin film and a second intermediate layer insulating film are sequentially formed therein, and the bonding pad portion of the upper layer metal thin film is projected upward in the bonding pad opening region to perform bonding. Since the upper edge of the protective insulating film around the pad is formed to be lower than the bonding pad part of the upper metal thin film, the normal ohmic electrode, two layers can be formed without adding a dedicated step for forming a dedicated bonding pad. A highly reliable bonding pad portion can be formed during the process of forming the metal wiring structure.

[Brief description of drawings]

FIG. 1 is a sectional view of a bonding pad portion of a semiconductor device according to a first exemplary embodiment.

FIG. 2 is a cross-sectional view showing the method of manufacturing the bonding pad portion of the semiconductor device according to the first embodiment.

FIG. 3 is a sectional view of a bonding pad portion of a semiconductor device according to a second embodiment.

FIG. 4 is a cross-sectional view showing the method of manufacturing the bonding pad portion of the semiconductor device according to the second embodiment.

FIG. 5 is a sectional view of a bonding pad portion of a conventional semiconductor device.

[Explanation of symbols]

101 semiconductor substrate 102 first layer insulating film (lower layer insulating film or first intermediate layer insulating film) 103 second layer insulating film (intermediate layer insulating film or second intermediate layer insulating film) 104 protective insulating film 110 lower layer metal thin film 111 Upper metal thin film 112 Ohmic electrode 120 Bonding pad opening 130, 140, 150 Photoresist pattern

Claims (5)

[Claims] 1. A two-layer wiring comprising a lower metal thin film and an upper metal thin film above a semiconductor substrate, and a protective insulating film for protecting the upper metal thin film, and a part of the protective insulating film. In a semiconductor device having a bonding pad opening region in, a lower insulating film is provided above the semiconductor substrate and below the protective insulating film, and the lower metal thin film is on the surface of the lower insulating film and the bonding pad. An intermediate insulating film is formed in a region to be in the opening region, on the surface of the lower metal thin film and its surrounding lower insulating film, and in a region to be in the bonding pad opening region, an intermediate insulating film is provided. The thin film is formed on the surfaces of the intermediate insulating film and the lower insulating film around the intermediate insulating film to form a bonding pad portion that protrudes upward on the intermediate insulating film. The protective insulating film is formed on the surface of the upper metal thin film and the surrounding lower insulating film around the upper metal thin film to expose the bonding pad portion of the upper metal thin film in the bonding pad opening region. A semiconductor device, wherein the height of the upper end surface is formed so as to be lower than the bonding pad portion of the upper metal thin film. 2. An ohmic metal thin film which is in ohmic contact with the semiconductor substrate above the semiconductor substrate, a two-layer wiring comprising a lower metal thin film and an upper metal thin film provided on the ohmic metal thin film, and the upper metal layer. In a semiconductor device having a protective insulating film provided on a thin film and having a bonding pad opening region in a part of the protective insulating film, the ohmic metal thin film is formed in the bonding pad opening region. A first intermediate insulating film is provided on the surface of the ohmic metal thin film and the surrounding lower insulating film, and in a region that is within the bonding pad opening region. A second intermediate layer is formed on the surface of the intermediate insulating film and the semiconductor substrate around it, and on the surface of the lower metal thin film and the semiconductor substrate around it. A layer insulating film is provided, and the upper metal thin film is a bonding pad projecting on the surface of the second intermediate insulating film and the lower insulating film around the second intermediate insulating film and at least above the first intermediate insulating film. And the protective insulating film is formed so as to expose the bonding pad portion of the upper metal thin film on the surface of the upper metal thin film and the peripheral semiconductor substrate and in the bonding pad opening region. A semiconductor device, which is formed, and whose upper end surface is formed at a height below the bonding pad portion. 3. The semiconductor device according to claim 1, wherein the upper metal thin film is formed so as to be electrically connected to the lower metal thin film. 4. A two-layer wiring consisting of a lower metal thin film and an upper metal thin film and a protective insulating film for protecting the upper metal thin film are provided above the semiconductor substrate, and a part of the protective insulating film is provided. A method of manufacturing a semiconductor device having a bonding pad opening region in a step of forming a lower insulating film above a semiconductor substrate, and a region on the surface of the protective insulating film and within the bonding pad opening region. A step of forming the lower layer metal thin film on the surface of the lower layer metal thin film and the surrounding lower layer insulation film, and a step of forming an intermediate layer insulation film in a region that is in the bonding pad opening region, Forming the upper metal thin film on the surface of the lower insulating film and the surrounding lower insulating film, and depositing a protective insulating film on the surfaces of the upper metal thin film and the lower insulating film, A step of forming the bonding opening region in the insulating film and exposing the bonding pad portion so that the upper end of the protective insulating film is lower than the bonding pad portion of the upper metal thin film. Manufacturing method. 5. An ohmic metal thin film in ohmic contact with the semiconductor substrate, a two-layer wiring formed of a lower metal thin film and an upper metal thin film, and a protective insulating film for protecting the upper metal thin film above the semiconductor substrate. A method of manufacturing a semiconductor device having a bonding pad opening area in a part of the protective insulating film, the method comprising forming an ohmic metal thin film on a surface of the semiconductor substrate in the bonding pad opening area. And a step of forming a first intermediate layer insulating film on the surface of the ohmic metal thin film and the semiconductor substrate around the ohmic metal thin film and in a region to be in the bonding pad opening region, and the first intermediate layer insulating film and its periphery. A step of depositing the lower layer metal thin film on the surface of the semiconductor substrate and in a region that is to be in the bonding pad opening region; Depositing a second intermediate-layer insulating film on the surface of the film and the semiconductor substrate around it; forming the upper-layer metal thin film on the surface of the second intermediate-layer insulating film and the semiconductor substrate around it; After depositing a protective insulating film on the surface of the upper metal thin film and the semiconductor substrate, the bonding opening region is formed in the protective insulating film, and the upper end of the protective insulating film is formed from the bonding pad portion of the upper metal thin film. And a step of exposing the bonding pad portion so that the bonding pad portion is also on the lower side.