JP6950447B2 - Semiconductor device - Google Patents

Description

The present invention relates to a semiconductor device including a semiconductor layer and a metal electrode layer bonded to the semiconductor layer, and more particularly to a metal electrode layer having a protective layer effective for preventing diffusion.

As a semiconductor device that functions by utilizing the semiconductor characteristics, there is one equipped with a thin film transistor. The thin film transistor (hereinafter referred to as "TFT") has three electrode layers of a gate, a source, and a drain, and has a semiconductor layer in which a channel region is formed in a region superimposed on the gate. It is desirable to use a metal material with a low electrical resistance value such as Al and Cu for the electrode layer of the TFT, but Al atoms and Cu atoms diffuse into the semiconductor layer by heat treatment during TFT manufacturing, and the characteristics of the TFT May deteriorate. Therefore, a protective layer (barrier membrane) made of Mo or Mo alloy is provided between the electrode layer and the semiconductor layer to prevent the diffusion of metal atoms.

However, when Al is used for the electrode layer, sufficient corrosion resistance cannot be ensured in combination with a conventional protective layer made of Mo or Mo alloy, and there is a risk that reliability will decrease due to corrosion of the Al electrode under high temperature and high humidity. there were.

In Patent Document 1 below, the source / drain electrode layer of the TFT is composed of a Cu thin film and a diffusion prevention thin film arranged between the Cu thin film and the oxide semiconductor layer, and the oxide semiconductor layer and the electrode layer are formed. It is disclosed that the point that the diffusion movement is prevented is made between the two. However, the anti-diffusion thin film disclosed here is composed of an oxide of Cu or a Cu alloy, and the composition of the protective layer (anti-diffusion thin film) is different from that of the present invention.

Japanese Unexamined Patent Publication No. 2014-239217

Against the background of the above circumstances, the present invention has been made for the purpose of providing a semiconductor device that suppresses diffusion of Al atoms in a metal electrode layer containing Al as a main component and has excellent corrosion resistance.

Therefore, claim 1 is a semiconductor device having a semiconductor layer and a metal electrode layer bonded to the semiconductor layer, and the metal electrode layer is mainly made of Al or an Al alloy of 90 at% or more. It has a layer and a first protective layer provided on the surface of the main layer on the semiconductor layer side, and the first protective layer contains Cu: 30 to 50% in mass%. Further, it is characterized by containing one selected from Ti: 3 to 5% and Cr: 3 to 5%, and composed of a NiCuTi alloy or a NiCuCr alloy having a composition of the balance Ni and unavoidable impurities.

In claim 2, in claim 1, an oxide conductive layer is formed on the side of the metal electrode layer opposite to the semiconductor layer, and the metal electrode layer is the oxide conductive layer of the main layer. It further has a second protective layer provided on the side surface, which is bonded to the oxide conductive layer by the second protective layer, and the second protective layer is Cu: 30 in mass%. It is composed of a NiCuTi alloy or a NiCuCr alloy containing ~ 50%, further containing one selected from Ti: 3 to 5%, Cr: 3 to 5%, and having a composition of the balance Ni and unavoidable impurities. It is characterized by.

In the present invention, the metal electrode layer to be bonded to the semiconductor layer is composed of a main layer made of Al or an Al alloy of 90 at% or more, and a first protective layer provided on the surface of the main layer on the semiconductor layer side. The first protective layer is a NiCuTi alloy or a NiCuCr alloy within a predetermined composition range.
Since the NiCuTi alloy or NiCuCr alloy within the predetermined composition range has a barrier effect of preventing the diffusion of Al atoms, the Al atoms in the metal electrode layer diffuse into the semiconductor layer under a high temperature environment, and the TFT It is possible to prevent the characteristics from deteriorating.

Further, if the combination of the main layer made of Al or 90 at% or more of Al alloy and the protective layer made of NiCuTi alloy or NiCuCr alloy within a predetermined composition range is used, the metal electrode can be used even in a high temperature and high humidity environment. Corrosion and discoloration of the layer can be suppressed satisfactorily.

Further, in the present invention, a second protective layer made of NiCuTi alloy or NiCuCr alloy can be provided on the surface of the main layer opposite to the semiconductor layer.
When joining an oxide conductive layer formed by using ITO (Indium Tin Oxide) or the like and a metal electrode layer, if the metal electrode layer is joined via the second protective layer, Al in the metal electrode layer can be joined. It is possible to ensure continuity between the oxide conductive layer and the metal electrode layer while satisfactorily preventing atoms from diffusing into the oxide conductive layer.

Next, the reasons for limiting the chemical components in the first protective layer and the second protective layer of the present invention will be described below. In the following description, "%" means "mass%" unless otherwise specified.

When the first protective layer or the second protective layer is formed of NiCuTi alloy, if the amount of Cu is too small, the adhesiveness is lowered. On the other hand, if the amount of Cu is too large, the amount of Ni in the balance is excessively reduced, and the barrier property and corrosion resistance are lowered. Therefore, the Cu content is set to 30 to 50%.
Further, when the amount of Cu is constant, the adhesion and corrosion resistance are improved as the amount of Ti is increased, but the etching property is lowered when the amount of Ti is too large. Therefore, the Ti content is set to 3 to 5%.

When the first protective layer or the second protective layer is formed of a NiCuCr alloy, if the amount of Cu is too small, the adhesion deteriorates. On the other hand, if the amount of Cu is too large, the amount of Ni in the balance is excessively reduced, and the barrier property and corrosion resistance are lowered. Therefore, the Cu content is set to 30 to 50%.
Further, when the amount of Cu is constant, the adhesion and corrosion resistance are improved as the amount of Cr is increased, but the etching property is lowered when the amount of Cr is too large. Therefore, the Cr content is set to 3 to 5%.

According to the present invention as described above, it is possible to provide a semiconductor device which suppresses diffusion of Al atoms in a metal electrode layer containing Al as a main component and has excellent corrosion resistance.

It is a schematic cross-sectional view of the semiconductor device of one Embodiment of this invention. It is explanatory drawing which shows the manufacturing procedure of the semiconductor device. It is explanatory drawing which shows the manufacturing procedure following FIG. It is explanatory drawing which shows the manufacturing procedure following FIG. It is explanatory drawing which shows the manufacturing procedure following FIG. It is a figure which showed the other form example of the semiconductor device.

Next, embodiments of the present invention will be described in detail below.
In FIG. 1, reference numeral 10 denotes a semiconductor device, which includes a TFT 12, an interlayer insulating layer 14 covering the TFT 12, and an oxide conductive layer 16 bonded to the TFT 12.

The TFT 12 includes a gate electrode layer 20 formed on the substrate 18, a gate insulating layer 22 covering the gate electrode layer 20, and a semiconductor layer 24 arranged so as to overlap the gate electrode layer 20 via the gate insulating layer 22. A source electrode layer 26 and a drain electrode layer 28 for joining with the semiconductor layer 24 are provided.

As the substrate 18, a glass substrate such as soda lime glass or non-alkali glass, or a resin substrate such as polyethylene terephthalate (PET) can be used. The thickness of the substrate 18 is preferably 300 μm to 1 mm from the viewpoint of workability.

It is desirable that the gate electrode layer 20 is formed of a low-resistance metal material such as Al or Cu, but for example, Al alone has problems such as inferior heat resistance and easy corrosion, so other heat-resistant conductivity. It can also be formed in combination with materials.

The gate insulating layer 22 may be a single layer or two or more layers, and conventionally commonly used ones such as a silicon oxide film (SiOx film) and a silicon nitride film (SiNx film) can be used.

The semiconductor layer 24 can be composed of an oxide semiconductor such as In—Ga—Zn-based oxide (also referred to as IGZO). The In-Ga-Zn-based oxide means an oxide containing In, Ga, and Zn as main components, and the ratio of In, Ga, and Zn does not matter. Further, a metal element other than In, Ga and Zn may be contained.
The semiconductor layer 24 is not limited to the oxide semiconductor, and for example, amorphous silicon (also referred to as a-Si) can be used.

The source electrode layer 26 and the drain electrode layer 28 are respectively bonded to the semiconductor layer 24. Specifically, a recess 29 is provided between the source electrode layer 26 and the drain electrode layer 28, and the source electrode layer 26 and the drain electrode layer 28 are separated from each other by the recess 29 and are bonded to the semiconductor layer 24, respectively. ing. The source electrode layer 26 and the drain electrode layer 28 are the metal electrode layers of the present invention, and may be collectively referred to as the metal electrode layer 30 below.

The source electrode layer 26 and the drain electrode layer 28, that is, the metal electrode layer 30, are a main layer 32 composed of Al alone, and a first protective layer 34 provided on the surface of the main layer 32 on the semiconductor layer 24 side. It has a laminated structure including a second protective layer 35 provided on a surface of the main layer 32 opposite to the semiconductor layer 24.

The main layer 32 is preferably composed of Al alone in order to have low resistance. Generally, Cu is used in addition to Al as the electrode material. Both Al and Cu can be processed by wet etching, but Cu cannot be processed by dry etching, so Al is more versatile. In terms of cost, Al is as inexpensive as about 1/3 of Cu.
When the main layer 32 is composed of Al alone, a film can be formed by non-reactive sputtering using a target material of pure Al. Further, in some cases, the main layer 32 may be made of an Al alloy having an Al content of 90 at% or more. The thickness of the main layer 32 is preferably 10 nm to 1 μm.

The first protective layer 34 and the second protective layer 35 are made of a NiCuTi alloy or a NiCuCr alloy and cover the lower surface and the upper surface of the main layer 32. The first protective layer 34 and the second protective layer 35 can be formed by non-reactive sputtering using a target material composed of a NiCuTi alloy or a NiCuCr alloy having a predetermined composition.
The composition of the first protective layer 34 and the second protective layer 35 may be the same as or different from each other. Common target materials can be used as long as they have the same composition. The thickness of the first protective layer 34 and the second protective layer 35 is set to 15 to 200 nm in order to reliably cover the surface of the main layer 32 containing Al as a main component to obtain sufficient corrosion resistance and diffusion barrier properties. It is preferable to do so.

The interlayer insulating layer 14 is arranged so as to cover the source electrode layer 26 and the drain electrode layer 28, and is in contact with the channel region 43 of the semiconductor layer 24 in the recess 29 between the source electrode layer 26 and the drain electrode layer 28. Have been placed. As the interlayer insulating layer 14, a silicon oxide film (SiOx film), a silicon nitride film (SiNx film), or the like can be used as in the gate insulating layer 22.

The oxide conductive layer 16 is composed of ITO, ZnO, SnO ₂ , IZO, etc., and is arranged on the interlayer insulating layer 14. If the semiconductor device 10 functions as a liquid crystal display device in this example, the oxide conductive layer 16 constitutes a pixel electrode in a liquid crystal display unit (not shown). The oxide conductive layer 16 is electrically connected to the drain electrode layer 28 via a connection hole 36 formed in the interlayer insulating layer 14, and when the TFT 12 is turned ON / OFF, the oxide conductive layer 16 is connected to the oxide conductive layer 16. The voltage application is started and stopped.

Next, the manufacturing process of the semiconductor device 10 will be described.
First, a first conductive film is formed on the substrate 18 by a vacuum thin film forming method such as a sputtering method or a thin film deposition method, and the first conductive film is patterned from Al or the like as shown in FIG. 2 (A). The gate electrode layer 20 is formed.

When the gate electrode layer 20 is formed by patterning the first conductive film, the surface of the substrate 18 is exposed except for the portion where the gate electrode layer 20 is located. As shown in FIG. 2B, a gate insulating layer 22 such as _{SiO 2} or SiNx is formed on the surfaces of the substrate 18 and the gate electrode layer 20.

Next, as shown in FIG. 2C, a semiconductor thin film is formed on the gate insulating layer 22, and then patterned to form a semiconductor layer 24 made of the patterned semiconductor thin film. For example, an oxide semiconductor layer made of an In—Ga—Zn-based oxide containing In, Ga, and Zn in a predetermined ratio is formed.

Next, as shown in FIGS. 3A, 3B, and 3C, the surface of the semiconductor layer 24 and the surface of the gate insulating layer 22 exposed at a place other than the portion where the semiconductor layer 24 is located are placed on the surface of the semiconductor layer 24. The protective film 34a of 1, the second conductive film 32a, and the second protective film 35a are laminated in this order.
The first protective film 34a uses a target material composed of a NiCuTi alloy or a NiCuCr alloy having a predetermined composition with respect to the laminate prepared up to the state shown in FIG. 2C, and is non-reactive with the target material as a sputtering gas. It is formed by non-reactive sputtering using gas.

Next, the second conductive film 32a is shown in FIG. 3B by non-reactive sputtering using a target material containing Al as a main component and a gas non-reactive with the target material as the sputtering gas. As described above, it is formed on the surface of the first protective film 34a.

Next, a second protective film 35a is formed by non-reactive sputtering using a target material composed of a NiCuTi alloy or a NiCuCr alloy having a predetermined composition and a gas that is non-reactive with the target material as the sputtering gas. ), It is formed on the surface of the second conductive film 32a. In this way, the metal electrode film 30a composed of the first protective film 34a, the second conductive film 32a, and the second protective film 35a is formed.

After that, as shown in FIG. 4A, a resist 38 is formed on the non-removed portion of the metal electrode film 30a, and in this state, the laminate containing the metal electrode film 30a is immersed in the etching solution to form the metal electrode film 30a. However, the portion not masked by the resist 38 is partially removed. After that, when the resist 38 is removed, as shown in FIG. 4B, a source electrode layer 26 and a drain electrode layer 28 having a first protective layer 34, a main layer 32, and a second protective layer 35 are formed. ..

In FIG. 4B, the channel region 43 is between the source region 41 and the drain region 42 of the semiconductor layer 24, and the gate electrode layer 20 is located at a position facing the channel region 43 with the gate insulating layer 22 interposed therebetween. .. In this state, the TFT 12 is composed of the semiconductor layer 24, the gate insulating layer 22, and the gate, source, and drain electrode layers 20, 26, and 28.

Here, in the source electrode layer 26 and the drain electrode layer 28, the first protective layer 34 is arranged between the main layer 32 made of Al or an Al alloy and the semiconductor layer 24. Since the first protective layer 34 made of NiCuTi alloy (or NiCuCr alloy) has a barrier function against Al atoms, diffusion of Al atoms from the main layer 32 to the semiconductor layer 24 is satisfactorily prevented. When the semiconductor layer 24 is an oxide semiconductor, the first protective layer 34 can prevent the diffusion of O atoms from the semiconductor layer 24 to the source electrode layer 26 and the drain electrode layer 28. Therefore, while using the semiconductor layer 24 as an oxide semiconductor, Al, which is more easily oxidized than Cu, can be used for the source electrode layer 26 and the drain electrode layer 28.

Next, as shown in FIG. 5A, an _{interlayer insulating layer 14 made of SiNx, SiO 2,} or the like is formed. At the same time, a connection hole 36 (see FIG. 1) is formed at a predetermined position of the interlayer insulating layer 14. Then, as shown in FIG. 5B, a third conductive film such as ITO is formed on the surface of the interlayer insulating layer 14, and then patterning is performed to form the oxide conductive layer 16.

At this time, as shown in FIG. 1, a part of the oxide conductive layer 16 is formed in the connection hole 36 and is joined to the drain electrode layer 28 exposed on the bottom surface of the connection hole 36. Specifically, it is joined to the second protective layer 35 of the drain electrode layer 28. Since the second protective layer 35 is made of a NiCuTi alloy (or NiCuCr alloy) and has a barrier function against Al atoms, the diffusion of Al atoms from the main layer 32 of the drain electrode layer 28 to the oxide conductive layer 16 is allowed. Well prevented. Further, the second protective layer 35 prevents the diffusion of O atoms from the oxide conductive layer 16 to the drain electrode layer 28. Therefore, even when Al, which is more easily oxidized than Cu, is used for the drain electrode layer 28, the oxide conductive layer 16 is passed through the second protective layer 35 while preventing the drain electrode layer 28 from being oxidized. It can be electrically connected to the drain electrode layer 28.

Although the configuration of the semiconductor device and the manufacturing method thereof according to the embodiment of the present invention have been described above, the configuration of the semiconductor device and the manufacturing method thereof can be appropriately changed. For example, when forming the source electrode layer 26 and the drain electrode layer 28, when an etching solution in which the semiconductor layer 24 is eroded is used, as shown in FIG. 6, a stopper is used so that the surface of the semiconductor layer 24 is not exposed. It is also possible to provide the layer 45 so that the etching solution does not come into contact with the semiconductor layer 24.

Next, examples of the present invention will be described below. Here, a laminate having the configuration shown in Table 1 and having the first protective film having the film composition shown in Table 2 was produced as follows, and the adhesion was measured and evaluated.

(Manufacturing of various laminates)
Size: Using a glass substrate of 10 cm x 10 cm, a first conductive film, an insulating film, a semiconductor film, a first protective film, a second conductive film, a second protective film, and a third conductive film are used on the substrate. Was laminated in this order.

The first conductive film was formed by using a pure Al sputtering target, setting the degree of vacuum to 5 × 10 ^-4 Pa, and introducing Ar gas (inert gas) into the chamber. The sputter pressure was 0.1 to 1.0 Pa, and the power was 100 to 500 W. The thickness of the first conductive film is 150 to 1000 nm.

For the film formation of the insulating film, oxygen and SiH _{4 were used as raw material gases, and the SiO 2} film was formed by the plasma CVD method. The thickness of the insulating film is 500 to 2000 nm.

For film formation of the semiconductor film, a sputtering target consisting of Ga: In: Zn: Sn = 16.8: 16.6: 47.2: 19.4 (atomic ratio) was used, and the degree of vacuum was 5 × 10 ^-4 Pa. Then, a sputtering gas containing oxygen and Ar was introduced into the chamber. The sputter pressure was 0.1 to 1.0 Pa, and the power was 100 to 500 W. The thickness of the semiconductor film is 30 to 200 nm.

For the formation of the first protective film, a sputtering target such as NiCuTi alloy or NiCuCr alloy corresponding to various compositions shown in Table 2 was used, the degree of vacuum was set to 5 × 10 ^-4 Pa, and Ar gas was introduced into the chamber. I went. The sputter pressure was 0.1 to 1.0 Pa, and the power was 100 to 500 W. The thickness of the first protective film is 15 to 200 nm.

The second conductive film was formed by using a pure Al sputtering target, setting the degree of vacuum to 5 × 10 ^-4 Pa, and introducing Ar gas into the chamber. The sputter pressure was 0.1 to 1.0 Pa, and the power was 100 to 500 W. The thickness of the second conductive film is 150 to 1000 nm.

The second protective film was formed by using a sputtering target of NiCuTi alloy or NiCuCr alloy, setting the degree of vacuum to 5 × 10 ^-4 Pa, and introducing Ar gas into the chamber. The sputter pressure was 0.1 to 1.0 Pa, and the power was 100 to 500 W. The thickness of the second protective film is 15 to 200 nm.
When the second protective film is a NiCuTi alloy, a sputtering target of Ni: 67%, Cu: 30%, Ti: 3% is used, and when the second protective film is a NiCuCr alloy, Ni: 67%, Cu A sputtering target of: 30% and Cr: 3% was used.

For the film formation of the third conductive film, a _{sputtering target composed of In 2} O ₃ containing 10% _{SnO 2} was used, the degree of vacuum was set to 5 × 10 ^-4 Pa, and a sputtering gas containing oxygen and Ar was placed in the chamber. I introduced it. The sputter pressure was 0.1 to 1.0 Pa, and the power was 100 to 500 W. The thickness of the third conductive film made of ITO is 30 to 200 nm.

(Adhesion test)
Adhesion tests in accordance with JIS K5600-5-6 were performed on each of the produced laminates. The target was set to be classified as 0 to 3 as defined by JIS K5600-5-6, and the evaluation was made according to the following evaluation criteria. The results are shown in Table 2.
◯: Adhesion is classified 0 to 3
X: Adhesion is classified as 4 or higher

As shown in Table 2, in Comparative Example 1 and Comparative Example 2, the first protective film was formed of a NiCu alloy in which the Cu content was below the lower limit of the present invention and Ti and Cr were not added. bottom. In both Comparative Example 1 and Comparative Example 2, the adhesion was classified as 4 or higher, and the evaluation of the adhesion was "x".
Good adhesion was obtained in each of the other Comparative Examples 3 to 8 and Examples 1 to 12.
From these results, in order to obtain good adhesion using the protective film of NiCu-based alloy, it is necessary to add Cu amount of 30 to 50% and Ti or Cr amount of 3 to 5%. I understand.

Next, a laminate having the composition shown in Table 3 and having the protective film having the film composition shown in Table 4 was produced, and the etching property, the barrier property and the corrosion resistance were evaluated by the following methods. Here, a semiconductor film, a protective film, and a conductive film were laminated and formed on the glass substrate in this order. The method for forming the semiconductor film, the protective film and the conductive film is the same as in the case of the semiconductor film, the first protective film and the second conductive film in the first embodiment.

(Etching property evaluation)
A 5 cm square sample was cut out from the prepared laminate, and this sample was immersed in an etching solution Cu-03 manufactured by Kanto Chemical Co., Inc., and the time until the film formed on the substrate was completely dissolved was measured. Evaluated at. The results are shown in Table 4.
◯: Time required for dissolution is less than 1 minute ×: Time required for dissolution is 1 minute or more

(Barrier evaluation)
Before and after the heat treatment, the prepared laminate was measured at 5 points on the metal film (Al film) by the 4-probe method, and the electrical resistivity (μΩ · cm) before and after the heat treatment was measured from the average value. Calculated. Then, the presence or absence of element diffusion was evaluated based on the following evaluation criteria from the change in the electrical resistivity value before and after the heat treatment. The heat treatment conditions were maintained in the air at 250 ° C. for 2 hours. The results are shown in Table 4.
◯: There is no change in the resistivity value before and after the heat treatment (change in resistivity is less than 10 μΩ · cm).
X: Compared with before heat treatment, the electrical resistivity value increased by 10 μΩ · cm or more after heat treatment.

(Evaluation of corrosion resistance)
Each of the prepared laminates was held in an air atmosphere environment of 85 ° C. × 85% RH (relative humidity) for 500 hours, and the presence or absence of discoloration of the laminate after holding was evaluated according to the following evaluation criteria in accordance with JIS C 60068. Evaluated at. The results are shown in Table 4.
⊚: No discoloration or film peeling at the center and edges of the sample before and after holding under the above environmental conditions ○: At least after holding, discoloration or film peeling is observed at the edges of the sample, but the edges of the sample are excluded. No discoloration or film peeling in the area ×: Discoloration or film peeling is observed at the center and edges of the sample, at least after holding.

In Table 4, in Comparative Example 11, the Ti content of the protective film made of NiCuTi alloy exceeds the upper limit of the present invention. Further, in Comparative Example 12, the Cr content of the protective film made of NiCuCr alloy exceeds the upper limit of the present invention. In Comparative Examples 11 and 12, although there is no problem in barrier property and corrosion resistance, the etching property is deteriorated, and when forming the source and drain electrode layers of the semiconductor device, patterning with one kind of etching solution is possible. difficult.

In Comparative Example 13, in the protective film made of NiCuTi alloy, the Cu content exceeds the upper limit of the present invention. Further, in Comparative Example 14, the Cu content of the protective film made of NiCuCr alloy exceeds the upper limit of the present invention. In Comparative Examples 13 and 14, although there is no problem in etching property, barrier property and corrosion resistance are deteriorated. From this, it is presumed that Cu itself has no effect of enhancing the barrier property and the corrosion resistance, and the barrier property and the corrosion resistance deteriorate as the relative amount of Ni decreases.

Comparative Example 15 is an example in which a protective film made of Mo alone is used. Further, Comparative Example 16 is an example in which a protective film made of MoTi alloy is used. In Comparative Examples 15 and 16, peeling of the film was observed after holding in a high temperature and high humidity environment. Conventionally, a protective film made of Mo or MoTi alloy, which has been used as a barrier film for preventing diffusion, cannot secure sufficient corrosion resistance in combination with an Al metal film, and there is a concern that reliability may decrease due to corrosion of the Al electrode. NS.

In the other Comparative Examples 9 and 10 and Examples 13 to 24, the results of etching property, barrier property and corrosion resistance were good. In particular, in the NiCuTi alloy or NiCuCr alloy, the adhesion results of Examples 13 to 16 and Examples 19 to 22 in which the Cu amount was suppressed and the Ni amount was 55% or more were better than those of the other examples. ..

In the above embodiment, IGZO is used as the semiconductor film, but the same result can be obtained with the laminated body of the configurations c and d in Table 1 and the configurations j and k in Table 3 in which a-Si is used instead of IGZO. Has been obtained.

Summarizing the above evaluation results, the combination of the metal film of Al and the protective film of Ni-30 to 50% Cu-3 to 5% Ti (Cr) alloy has adhesion, barrier property, corrosion resistance, and etching property. Is excellent. If such a combination is applied to the metal electrode layer of a semiconductor device, it can be expected that high barrier properties and high corrosion resistance will be exhibited even in the semiconductor device.

The embodiments and examples of the present invention have been described in detail above, but these are merely examples. The present invention can be carried out in a manner in which various modifications are made without departing from the spirit of the present invention.

10 Semiconductor device 16 Oxide conductive layer 24 Semiconductor layer 30 Metal electrode layer 32 Main layer 34 First protective layer 35 Second protective layer

Claims (2)

A semiconductor device having a semiconductor layer and a metal electrode layer bonded to the semiconductor layer.
The metal electrode layer has a main layer made of Al or an Al alloy of 90 at% or more, and a first protective layer provided on the surface of the main layer on the semiconductor layer side.
The first protective layer contains Cu: 30 to 50% in mass%, and further contains one selected from Ti: 3 to 5% and Cr: 3 to 5%, and the balance Ni and A semiconductor device comprising a NiCuTi alloy or a NiCuCr alloy having an unavoidable composition of impurities. In claim 1, an oxide conductive layer is formed on the side of the metal electrode layer opposite to the semiconductor layer, and the oxide conductive layer is formed.
The metal electrode layer further has a second protective layer provided on the surface of the main layer on the oxide conductive layer side, and is bonded to the oxide conductive layer by the second protective layer.
The second protective layer contains Cu: 30 to 50% in mass%, and further contains one selected from Ti: 3 to 5% and Cr: 3 to 5%, and the balance Ni and A semiconductor device comprising a NiCuTi alloy or a NiCuCr alloy having an unavoidable impurity composition.

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