JP2000091369A - Semiconductor device and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductor device, which can realize cost reduction by forming a bump on an electrode pad by the simple process and manufacturing method thereof. SOLUTION: A Cu wiring layer and the Cu electrode pad 12 formed on an Si wafer 10 are covered with a passivation film 14. On the Cu electric pad 12, a Cu layer 16 having a thickness of about 1 μm, which is formed by the electroless strike plating method through the opening hole part of the passivation film 14, and an Ni barrier layer 18 having a thickness of about 0.5-5 μm formed by the electroless plating method are laminated. On the Ni barrier layer 18, a mushroom-shaped Au bump 20 with a height of about 5-30 μm is formed by the electroless plating method. That is to say, the mushroom-type Au bump 20 is formed on the Cu electrode pad 12 via the Cu layer 16 and the Ni barrer layer 18.

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 semiconductor device having a bump as a protruding connection electrode formed on a semiconductor chip and a method of manufacturing the same. is there.

[0002]

2. Description of the Related Art In a semiconductor device, which is a key part used for electrical equipment such as a television, an audio, a telephone, and a personal computer, the number of inputs and outputs tends to increase year by year as the number of gates increases. (Wire
Bonding) A method of assembling using bump wiring which does not require wiring and is suitable for high-density packages has been adopted.

Incidentally, Al (aluminum) has conventionally been used as a material for wiring in such a semiconductor device. This is because Al has excellent conductive properties and its film formation and processing are easy.
Therefore, in a conventional semiconductor device, a bump is formed on an Al electrode pad. Hereinafter, a conventional typical method of forming a bump on this Al electrode pad will be described.
This will be described with reference to FIGS.

For example, after forming predetermined elements on a Si (silicon) wafer 60, an Al wiring layer for electrically connecting these elements and an Al electrode pad 62 at an end thereof are formed, and further, a passivation film is formed on the entire surface of the substrate. 64. Subsequently, the passivation film 64 on the Al electrode pad 62 is selectively etched away to expose the surface of the Al electrode pad 62 (see FIG. 16).

Next, a first-layer barrier film made of a material having high adhesion to Al, for example, a Ti (titanium) film is deposited on the entire surface of the substrate by using an evaporation method. Second-layer barrier film made of a material having a high
In the case of a u bump, a Ni (nickel) film is deposited, and subsequently, a third barrier film made of the same material as the bump, for example, in the case of an Au (gold) bump, an Au film is deposited. Here, a Cr (chromium) film or the like may be used instead of the Ti film, or a W (tungsten) film or the like may be used instead of the Ni film. Thus, the first layer Ti film, the second layer Ni film, and the third layer Au
Ti / Ni / Au barrier film 6 having a three-layer structure in which films are stacked
6 is formed (see FIG. 17).

Next, the Ti / Ni / Au barrier film 6
After applying a resist 68 on the upper surface 6, the resist 68 is patterned into a predetermined shape using a photolithography technique to form an opening above the Al electrode pad 62,
The surface of the Ti / Ni / Au barrier film 66 in this opening is exposed (see FIG. 18).

Next, using a plating method, Ti / Ni /
Au plating is selectively performed on the Au barrier film 66, and Au plating is performed.
The bump 70 is formed (see FIG. 19). After that,
The resist 68 is removed (see FIG. 20).

Next, after a resist 72 is applied to the entire surface of the substrate, the resist 72 is patterned into a predetermined shape to cover the Au bump 70 and the surrounding Ti / Ni / Au barrier film 66 by using a photolithography technique (FIG. 2
1).

Subsequently, the Ti / Ni / Au barrier film 66 is selectively etched by using the resist 72 patterned in a predetermined shape as a mask, thereby forming a passivation film 64.
All exposed Ti / Ni / Au barrier films 66
Is removed. Thereafter, the resist 72 is removed. Thus, the Ti / Ni /
An Au bump 70 is formed via the Au barrier film 66 (see FIG. 22).

In addition to the method of forming the Au bump 70 on the Al electrode pad 62, an Au wire ball is formed at the tip of the caterpillar using a bonding apparatus, and the Au ball is heated and super-heated. Bonding on the Al electrode pad using sound waves, and A on the Al electrode pad
There is also a technique called a stat bump method of crushing a u-ball to form an Au bump.

[0011]

In the above-described conventional method of forming the Au bump 70 on the Al electrode pad 62, when forming the Ti / Ni / Au barrier film 66 on the Al electrode pad 62, the vapor deposition method is used. Is used. here,
It is difficult to form a plating film on the Al electrode pad 62 because Al has a property of being easily oxidized and a thin Al oxide film of 3 to 20 nm is naturally formed on the surface of the Al electrode pad 62. There is a situation that is.
Therefore, a deposition process is required to form the Ti / Ni / Au barrier film 66, and accordingly, a photolithography technique is used to remove unnecessary portions of the deposited Ti / Ni / Au barrier film 66. For example, it is necessary to perform a patterning process of the resist 72 using the mask and an etching process using the resist 72 as a mask, thereby complicating the process and complicating the process, thereby increasing the cost.

Also, when forming an Au bump by the stat bump method, the Au bump is formed on the Al electrode pad.
In addition to the step of forming the ball, a step of crushing the Au ball to form an Au bump is also required, so that there is a problem that the manufacturing process requires a long time and the cost increases.

Furthermore, with the recent increase in the speed of semiconductor devices, there is a tendency to use Cu (copper) having higher conductivity than Al as a wiring material. Accordingly, it is possible to cope with the recent tendency to use Cu as the wiring material,
It has been an issue to develop a technology that solves problems such as complicated and complicated steps in forming an Au bump on an l-electrode pad.

The present invention has been made in view of the above circumstances, and provides a semiconductor device and a method of manufacturing the same, which can realize a reduction in cost by forming bumps on electrode pads by a simple process. The purpose is to provide.

[0015]

The above objects can be attained by the following semiconductor device and a method of manufacturing the same according to the present invention. That is, the semiconductor device according to claim 1 includes an electrode pad made of Cu or a Cu alloy formed on a semiconductor substrate;
And a bump formed on the electrode pad via a barrier metal layer. As described above, in the semiconductor device according to the first aspect, the bump is formed on the electrode pad made of Cu or Cu alloy having higher conductivity than Al which is a conventional wiring material via the barrier metal layer. Accordingly, a high-density semiconductor device package capable of high-speed operation is realized.

In the semiconductor device according to the first aspect, the barrier metal layer formed on the electrode pad made of Cu or Cu alloy may be a Ni barrier layer, a W barrier layer, or a Pd (palladium) barrier layer. It is preferred to use. Unlike the case where these barrier metal layers are formed on a conventional Al electrode pad, these barrier metal layers are easily formed by using a plating method on an electrode pad made of Cu or Cu alloy. Good adhesion is obtained between the two.

In the semiconductor device according to the first aspect of the present invention, it is preferable to use a noble metal bump or a solder bump as a bump formed on the electrode pad made of Cu or a Cu alloy via a barrier metal layer. . Since these bumps are excellent in bonding characteristics at the time of assembling the semiconductor device, stable reliability after assembling can be obtained. In the case of solder bumps, Sn
It can be easily joined to a Cu lead plated with (tin), Au, Ag (silver), or solder. Examples of the noble metal bump include an Au bump, an Ag bump, a Pt (platinum) bump, and the like.

According to a fourth aspect of the present invention, there is provided a method of manufacturing a semiconductor device, comprising: a first step of forming an electrode pad made of Cu or a Cu alloy on a semiconductor substrate; and forming a barrier metal on the electrode pad by plating. A second step of forming a layer;
A third step of forming a bump on the barrier metal layer by using a plating method. Thus, in the method for manufacturing a semiconductor device according to claim 4,
Since a plating method is used when forming a barrier metal layer on an electrode pad made of u or Cu alloy, a vapor deposition process is not required unlike the case of a conventional Al electrode pad, so that inexpensive equipment is used. Since it is easily formed, the manufacturing cost is reduced. Further, a photolithography step and an etching step for removing an unnecessary portion of the deposited barrier metal film are eliminated, and the steps are simplified and the number of steps is reduced, so that the delivery time is shortened and the cost is reduced.

According to a fifth aspect of the present invention, in the method of manufacturing a semiconductor device according to the fourth aspect of the present invention, the semiconductor device is made of Cu or a Cu alloy between the first step and the second step. With the configuration having the step of performing Cu strike plating on the electrode pad, it becomes possible to form a barrier metal layer on the Cu strike plating layer immediately after film formation, so that the Cu strike plating layer and the barrier metal layer Good adhesion, and good adhesion between the electrode pad made of Cu or Cu alloy and the barrier metal layer via the Cu strike plating layer can be obtained.

According to a sixth aspect of the present invention, in the method of manufacturing a semiconductor device according to the fourth aspect, the plating method used in the second and third steps is an electroless plating method. With this, the barrier metal layer can be easily formed on the electrode pad made of Cu or Cu alloy using extremely simple equipment, and the bump can be easily formed on the barrier metal layer. .
In this case, unlike the case of the conventional Al electrode pad,
If the material of the barrier metal layer is appropriately selected, Cu or Cu
Good adhesion is obtained between the electrode pad made of the alloy and the barrier metal layer formed thereon by the electroless plating method. Suitable materials for the barrier metal layer include, for example, Ni, W, and Pd. In addition, this means that the second
This does not mean that the plating method used in the third step must be an electroless plating method. That is, even if the electrolytic plating method is used, it is possible to form a barrier metal layer on an electrode pad made of Cu or a Cu alloy, and to form a bump on the barrier metal layer. However, in this case, it is necessary to provide a common conducting path for performing the electrolytic plating, and it is necessary to remove the unnecessary common conducting path after the electrolytic plating.

[0021]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.
An embodiment of the present invention will be described. (First Embodiment) FIG. 1 is a sectional view showing a semiconductor device according to a first embodiment of the present invention, and FIGS. 2 to 10 are steps for explaining a method of manufacturing the semiconductor device of FIG. It is sectional drawing. As shown in FIG. 1, in the semiconductor device according to the present embodiment, predetermined elements (not shown) are formed on a surface layer of a Si wafer 10, and a Cu wiring layer ( (Not shown) and a Cu electrode pad 12 located at the end thereof are formed on the Si wafer 10. Further, the entire surface of the substrate including the Cu wiring layer and the Cu electrode pad 12 is covered with a passivation film 14 as a protective film.

On the Cu electrode pad 12, through an opening formed in the passivation film 14, for example, a 1 μm thick film formed by electroless strike plating.
A Cu layer 16 having a thickness of about m and a Ni barrier layer 18 having a thickness of, for example, about 0.5 to 5 μm formed by an electroless plating method are sequentially laminated. The Ni barrier layer 18 has a height of, for example, 5 mm, formed by electroless plating.
A mushroom type Au bump 20 of about 30 μm is provided. That is, on the Cu electrode pad 12, Cu
A mushroom type Au bump 20 is formed via the layer 16 and the Ni barrier layer 18.

Here, the Cu electrode pads 12 and C
The reason why the Ni barrier layer 18 is interposed between the u layer 16 and the Au bump 20 is that the Cu layer 16 and the Au bump 20 are kept in close contact with each other, and that the Cu bump 16 A in the layer 16 and the Cu electrode pad 12
This is to prevent u from diffusing.

Next, a method of manufacturing the semiconductor device shown in FIG. 1 will be described with reference to the process sectional views of FIGS. Si
After forming predetermined elements (not shown) on the surface layer of the wafer 10, a Cu wiring layer (not shown) for electrically connecting these elements and a Cu electrode pad 1 located at an end thereof are provided.
Form 2 Subsequently, a passivation film 14 as a protective film is deposited on the entire surface of the substrate, and the passivation film 14 covers the Cu wiring layer and the Cu electrode pads 12. Thereafter, the passivation film 14 on the Cu electrode pad 12 is selectively removed by etching to expose the surface of the Cu electrode pad 12 (see FIG. 2).

Next, as a pre-stage for performing a plating process, an alkali degreasing process, a water washing, and an acid washing of the Si wafer 10 are sequentially performed. Subsequently, as shown in FIG. 3, the Si wafer 10 is suspended by the arm 22 and immersed in a Cu plating solution 26 in a predetermined container 24. Thus, a Cu layer 16 having a thickness of about 1 μm is formed on the Cu electrode pad 12 by the electroless strike plating method (see FIG. 4).

Here, the Cu layer 16 made of the same material is formed on the Cu electrode pad 12 because the Ni barrier layer is formed on the Cu electrode pad 12 after a considerable time has passed since its formation. The Cu layer 16 immediately after film formation
This is because forming a Ni barrier layer on the top can obtain better adhesion with the Ni barrier layer.

Next, after the Si wafer 10 is washed again with water, the Si wafer 10 is suspended by the arm 22 and immersed in the Ni plating solution 30 in a predetermined container 28 as shown in FIG. Thus, the Ni barrier layer 18 having a thickness of about 0.5 to 5 μm is formed on the Cu electrode pad 12 by the electroless plating method (see FIG. 6).

Next, after water washing and alkali treatment of the Si wafer 10 are again performed in order, as shown in FIG.
The wafer 10 is suspended by the arm 22 and immersed in an Au plating solution 34 in a predetermined container 32. Thus, by the electroless plating method, a thickness of 1 to 2 is formed on the Ni barrier layer 18.
An Au layer 36 of about μm is formed (see FIG. 8).

Subsequently, as shown in FIG. 9, an Au layer is further formed on the Au layer 36 by using a spray-type plating device 38. That is, after the Au plating solution 42 in a predetermined container 40 of the spray type plating device 38 is sucked by the pump 44, the Au plating solution 42 is supplied to the injection nozzle 48 through the valve 46, and further, the face down from the injection nozzle 48 is performed. Au toward the surface of the Si wafer 10 placed on the
The plating solution 42 is sprayed. Thus, for example, a height of 5 including the Au layer 36 already formed by the electroless plating method.
A mushroom type Au bump 20 of about 30 μm is formed. Further, the Si wafer 10 is washed with water, and then drained and dried with hot air to manufacture the semiconductor device shown in FIG. 1 (see FIG. 10).

Here, the spray type plating apparatus 3
The reason for using 8 is to achieve a uniform plating thickness in the final thick plating that most affects the height of the Au bump 20. That is, this spray type plating apparatus 3
By using 8, the height of the Au bump 20 is kept constant.

Thereafter, although not shown, the Si wafer 1
Then, a semiconductor chip having a mushroom type Au bump 20 formed on the Cu electrode pad 12 via the Cu layer 16 and the Ni barrier layer 18 is cut out. Then, the semiconductor chip is assembled.

As described above, according to the semiconductor device of this embodiment, the Cu layer 16 and the Ni layer
Mushroom type Au bump 2 via barrier layer 18
By forming 0, it is possible to realize a high-density package of a semiconductor device capable of high-speed operation using a Cu wiring having higher conductivity than the conventional Al wiring.

Further, according to the method of manufacturing the semiconductor device according to the present embodiment, when the Ni barrier layer 18 is formed on the Cu electrode pad 12 via the Cu layer 16 by using the electroless plating method. Since no vapor deposition process is required as in the case of the conventional Al electrode pad, it can be easily manufactured using inexpensive equipment, and the manufacturing cost can be reduced. In addition, since a photolithography step and an etching step for removing an unnecessary portion of the deposited barrier metal film are eliminated, the steps are simplified and the number of steps is reduced, so that the delivery time is shortened and the cost is reduced. be able to.

Further, before the step of forming the Ni barrier layer 18, the Cu layer 16 is formed on the Cu electrode pad 12 by the electroless strike plating method, so that the Ni barrier layer 18 is formed, so that the Cu layer 16 and the Ni barrier layer 18 have good adhesion, and hence the Cu electrode pad 1 via the Cu layer 16.
2 and the Ni barrier layer 18 can be obtained with good adhesion, and the reliability of the semiconductor device can be improved.

In the first embodiment, the mushroom type Au bump 2 having a height of about 5 to 30 μm is used.
Although 0 is formed, when the height is sufficiently high, for example, about 50 μm, the Au bump 20 expands in the lateral direction when the mushroom type Au bump 20 is formed by the electroless plating method. As a result, the width is almost the same as the height. Therefore, when it is necessary to make the height of the Au bump sufficiently high, when forming the Au bump by the electroless plating method, the swelling in the lateral direction is suppressed, and the sufficiently high desired height is obtained. Is required to be easily realized. In response to this request, there is a second embodiment described below.

(Second Embodiment) FIG. 11 shows a second embodiment of the present invention.
1 is a cross-sectional view illustrating a semiconductor device according to an embodiment, and FIG.
2 to 15 are process cross-sectional views for describing a method of manufacturing the semiconductor device of FIG. The same components as those of the semiconductor device of the first embodiment shown in FIGS. 1 to 10 are denoted by the same reference numerals, and description thereof is omitted. FIG.
As shown in FIG. 1, in the semiconductor device according to the present embodiment, predetermined elements (not shown) are formed on the surface layer of the Si wafer 10, and C that electrically connects these elements is formed.
A u wiring layer (not shown) and a Cu electrode pad 12 located at an end thereof are formed on the Si wafer 10. Further, the entire surface of the substrate including the Cu wiring layer and the Cu electrode pad 12 is covered with a passivation film 14 as a protective film.

On the Cu electrode pad 12, through an opening formed in the passivation film 14, for example, a 1 μm thick film formed by electroless strike plating.
A Cu layer 16 having a thickness of about m and a Ni barrier layer 18 having a thickness of, for example, about 0.5 to 5 μm formed by an electroless plating method are sequentially laminated. The Ni barrier layer 18 has a height of, for example, 3 mm, formed by electroless plating.
A straight wall type Au bump 50 of about 0 to 50 μm is provided. That is, a straight wall Au bump 50 is formed on the Cu electrode pad 12 via the Cu layer 16 and the Ni barrier layer 18.

Next, a method of manufacturing the semiconductor device shown in FIG. 11 will be described with reference to the process sectional views of FIGS. By a process similar to the process shown in FIGS. 1 to 6 of the first embodiment, predetermined elements (not shown) are formed on the surface layer of the Si wafer 10 and these elements are electrically connected. C
After forming a u wiring layer (not shown) and a Cu electrode pad 12 located at the end thereof, a passivation film 14 as a protective film is deposited on the entire surface of the substrate to cover the Cu wiring layer and the Cu electrode pad 12, The passivation film 14 on the Cu electrode pad 12 is selectively removed by etching,
The surface of the electrode pad 12 is exposed.

Thereafter, the Si wafer 10 was subjected to alkali degreasing treatment, water washing, and pickling in this order, and was then electrolessly strike-plated on the Cu electrode pad 12 to a thickness of 1 μm.
Approximately a Cu layer 16 is formed. Subsequently, after the Si wafer 10 is again washed with water, Cu is removed by electroless plating.
A Ni barrier layer 18 having a thickness of about 0.5 to 5 μm is formed on the electrode pad 12 (see FIG. 12).

Next, after a resist 52 is applied to the entire surface of the substrate, the resist 52 is patterned into a predetermined shape by using a photolithography technique, and Au to be formed later is formed.
An opening having the size of a bump is formed, and Ni
The surface of the barrier layer 18 is exposed (see FIG. 13).

Next, FIGS. 7 to 9 of the first embodiment.
After the washing and the alkali treatment of the Si wafer 10 are sequentially performed by the same process as the process shown in FIG. 1, the A-layer having a thickness of about 1 to 2 μm
u layer is formed, and A is sprayed using a spray-type plating apparatus.
A u layer is formed. Thus, the straight wall Au bump 50 having a height of, for example, about 30 to 50 μm is formed by the electroless plating method. Further, the Si wafer 10 is washed with water, and then drained and dried with hot air.
The semiconductor device shown in FIG. 11 is manufactured (see FIG. 15).

Thereafter, although not shown, the Si wafer 1
Then, the semiconductor chip having the straight wall Au bump 50 formed on the Cu electrode pad 12 via the Cu layer 16 and the Ni barrier layer 18 is cut out. Then, the semiconductor chip is assembled.

As described above, according to the semiconductor device of this embodiment, the Cu layer 16 and the Ni layer
Since the straight wall type Au bumps 50 are formed via the barrier layer 18, the density of the package of a semiconductor device capable of high-speed operation using Cu wiring having higher conductivity than conventional Al wiring is increased. Can be realized.

Further, according to the method of manufacturing the semiconductor device according to the present embodiment, when the Ni barrier layer 18 is formed on the Cu electrode pad 12 via the Cu layer 16 by using the electroless plating method, Before the step of forming the Ni barrier layer 18, the Cu electrode pad 1 is formed by an electroless strike plating method.
Since the formation of the Cu layer 16 on the second substrate 2 is the same as that of the first embodiment, the same effect as that of the first embodiment can be obtained.

When forming the straight wall type Au bump 50 on the Ni barrier layer 18, the resist 52 applied on the entire surface of the substrate is patterned to form an opening of the size of the Au bump. Ni exposed to
By forming the Au bumps 50 on the barrier layer 18, the patterned resist 52 functions as a guide for suppressing the swelling of the Au bumps 50 in the lateral direction, so that the height of the Au bumps 50 is reduced to, for example, about 50 μm. Even if it is desired to make the height sufficiently high, the desired height can be easily realized.

In the first and second embodiments, the Cu electrode pad 12 located at the end of the Cu wiring layer is used.
A mushroom type Au bump 20 and a straight wall type Au bump 50 are formed on a Cu layer 16 and a Ni barrier layer 18 via a Cu layer 16 and a Ni barrier layer 18. Instead of the Cu wiring layer and the Cu electrode pad 12, a Cu alloy is used. The same effect can be obtained by using the wiring layer and the electrode pad.

The Cu layer 16 provided between the Cu electrode pad 12 and the Ni barrier layer 18 has a function of ensuring good adhesion to the Ni barrier layer, but may be omitted in some cases. You may.

Further, instead of the Ni barrier layer 18, for example, a W barrier layer or a Pd barrier layer may be used. Also in this case, the barrier metal layer having excellent adhesion to the Cu electrode pad 12 or the Cu layer 16 and intervening between the Cu electrode pad 12 or the Cu layer 16 and the Au bumps 20 and 50 to prevent the diffusion of Au is used. Functions can be demonstrated.

Also, instead of the Au bumps 20 and 50,
For example, an Ag bump or a Pt bump may be used. Alternatively, a solder bump having good adhesion to the Ni barrier layer 18 may be used. In any case, excellent bonding characteristics can be exhibited when assembling the semiconductor device.

Further, in the first and second embodiments, when forming the mushroom type Au bump 20 and the straight wall type Au bump 50, as shown in FIG. After immersing in an Au plating solution 34 to form an Au layer 36 having a thickness of about 1 to 2 μm, as shown in FIG.
Are used to form the Au bumps 20 and 50. However, the Au bumps 20 and 50 are immersed in the Au plating solution 34 of the previous stage to form the Au layer 36.
May be omitted, and the Au bump 20 and the Au bump 50 may be immediately formed using the subsequent spray plating apparatus 38.

The Cu layer 16, the Ni barrier layer 18, A
When forming the u layer 36 and the Au bumps 20 and 50, the electroless plating method is used in each case, but the invention is not limited to this, and the electro bumping method may be used. However, in this case, it is necessary to provide a common conducting path for performing the electrolytic plating, and it is necessary to remove the unnecessary common conducting path after the electrolytic plating.

[0052]

As described above, according to the semiconductor device and the method of manufacturing the same of the present invention, the following effects can be obtained. That is, according to the semiconductor device of the first aspect, on the electrode pad made of Cu or Cu alloy, which has higher conductivity than Al which is a conventional wiring material,
For example, via a barrier metal layer such as a Ni barrier layer, a W barrier layer, or a Pd barrier layer, for example, an Au bump, an Ag
Since a noble metal bump such as a bump or a Pt bump or a bump such as a solder bump is formed, a high-density semiconductor device package capable of high-speed operation can be realized.

According to the method of manufacturing a semiconductor device of the third aspect, the plating method is used when forming the barrier metal layer on the electrode pad made of Cu or Cu alloy, so that the conventional Al electrode Since a vapor deposition process is not required unlike the case of the pad, it can be easily manufactured using inexpensive equipment, and the manufacturing cost can be reduced. In addition, photolithography and etching steps are eliminated to remove unnecessary portions of the deposited barrier metal film, which simplifies the steps and reduces the number of steps, thereby shortening the delivery time and reducing costs. Can be.

Further, according to the method of manufacturing a semiconductor device of the fourth aspect, immediately before the step of forming the barrier metal layer, the Cu
Or, by applying Cu strike plating on the electrode pad made of Cu alloy, a barrier metal layer will be formed on the Cu strike plating layer immediately after film formation,
Good adhesion between the Cu strike plating layer and the barrier metal layer, and thus C through the Cu strike plating layer
Good adhesion between the electrode pad made of u or Cu alloy and the barrier metal layer can be obtained, and the reliability of the semiconductor device can be improved.

According to the method of manufacturing a semiconductor device of the fifth aspect, since the plating method for forming the barrier metal layer and the bump is an electroless plating method, Cu or Cu can be formed using extremely simple equipment. The barrier metal layer can be easily formed on the electrode pad made of Cu alloy with good adhesion, and the bump can be easily formed on the barrier metal layer with good adhesion.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a semiconductor device according to a first embodiment of the present invention.

FIG. 2 is a process sectional view (part 1) for describing the method for manufacturing the semiconductor device shown in FIG. 1;

FIG. 3 is a process sectional view (part 2) for describing the method for manufacturing the semiconductor device shown in FIG. 1;

FIG. 4 is a process sectional view (part 3) for describing the method for manufacturing the semiconductor device shown in FIG.

FIG. 5 is a process sectional view (part 4) for describing the method for manufacturing the semiconductor device shown in FIG.

FIG. 6 is a process sectional view (part 5) for describing the method for manufacturing the semiconductor device shown in FIG.

FIG. 7 is a process sectional view (part 6) for describing the method for manufacturing the semiconductor device shown in FIG.

FIG. 8 is a process sectional view (part 7) for describing the method for manufacturing the semiconductor device shown in FIG.

FIG. 9 is a process sectional view (part 8) for explaining the method for manufacturing the semiconductor device shown in FIG. 1;

FIG. 10 is a process sectional view (part 9) for describing the method for manufacturing the semiconductor device shown in FIG. 1;

FIG. 11 is a sectional view showing a semiconductor device according to a second embodiment of the present invention.

FIG. 12 is a process sectional view (part 1) for describing the method for manufacturing the semiconductor device shown in FIG. 11;

13 is a process sectional view (part 2) for describing the method for manufacturing the semiconductor device shown in FIG.

FIG. 14 is a process sectional view (part 3) for describing the method for manufacturing the semiconductor device shown in FIG. 11;

FIG. 15 is a process sectional view (part 4) for describing the method for manufacturing the semiconductor device shown in FIG.

FIG. 16 is a process sectional view (part 1) for describing a conventional method of forming a bump on an Al electrode pad.

FIG. 17 is a process sectional view (part 2) for describing a conventional method of forming a bump on an Al electrode pad.

FIG. 18 is a process sectional view (part 3) for describing a conventional method of forming a bump on an Al electrode pad.

FIG. 19 is a process sectional view (part 4) for describing a conventional method of forming a bump on an Al electrode pad.

FIG. 20 is a process sectional view (part 5) for describing a conventional method of forming a bump on an Al electrode pad.

FIG. 21 is a process sectional view (part 6) for describing a conventional method of forming a bump on an Al electrode pad.

FIG. 22 is a process sectional view (part 7) for describing a conventional method of forming a bump on an Al electrode pad.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Si wafer, 12 ... Cu electrode pad, 14 ... Passivation film, 16 ... Cu layer formed by electroless strike plating, 18 ... Ni barrier layer formed by electroless plating, 20 ... Electroless plating Mushroom-shaped Au bumps formed by
Arm, 24: container, 26: Cu plating solution, 28: container, 30: Ni plating solution, 32: container, 34: Au plating solution, 36: Au layer, 38: spray-type plating device,
40 ... container, 42 ... Au plating solution, 44 ... pump, 46
... Valve, 48 ... Injection nozzle, 50 ... Straight wall type Au bump formed by electroless plating, 52
... resist, 60 ... Si wafer, 62 ... Al electrode pad, 64 ... passivation film, 66 ... Ti / Ni / A
u barrier film, 68 resist, 70 Au bump, 72
... resist.

Claims (6)

[Claims] 1. A semiconductor device comprising: an electrode pad made of copper or a copper alloy formed on a semiconductor substrate; and a bump formed on the electrode pad via a barrier metal layer. 2. The semiconductor device according to claim 1, wherein said barrier metal layer is a nickel barrier layer, a tungsten barrier layer, or a palladium barrier layer. 3. The semiconductor device according to claim 1, wherein the bump is a noble metal bump or a solder bump. A first step of forming an electrode pad made of copper or a copper alloy on the semiconductor substrate; a second step of forming a barrier metal layer on the electrode pad by using a plating method; A third step of forming a bump on the barrier metal layer by using a plating method. 5. The method of manufacturing a semiconductor device according to claim 4, further comprising a step of performing copper strike plating on said electrode pad between said first step and said second step. Semiconductor device manufacturing method. 6. The method of manufacturing a semiconductor device according to claim 4, wherein the plating method used in the second and third steps is an electroless plating method.