JP3110795B2 - Method for manufacturing semiconductor device - Google Patents

Abstract

PURPOSE:To prevent the side etching of a diffusion preventing metal layer due to battery effect by performing the etching of the diffusion preventing metal formed between a wiring and a bump by using a resist layer as a mask. CONSTITUTION:An aluminum layer 2 and a diffusion preventing layer 3 are laminated and formed in order on a semiconductor layer 2, and the aluminum wiring layer 2 covered with the diffusion preventing metal layer 3 is formed by patterning. An aperture 5 is formed. A metal layer 6 for a current path and an adhesion reinforcement metal layer 7 are laminated and formed in order. A resist layer 8 is formed and eliminated from the region except a bump forming region by patterning. The adhesion reinforcement metal layer 7 is eliminated from the region except the bump forming region by etching using aqua regia. The resist layer 8 is eliminated and a resist layer 9 is newly formed. Said layer 9 is patterned and eliminated from the bump forming region. Thus, an aperture 10 is formed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an improvement in a bump forming method for a semiconductor device.

[0002]

2. Description of the Related Art FIG. 3 shows a process diagram of forming a bump according to the prior art.

As shown in FIG. 1A, an insulating film 4 such as PSG is formed on a semiconductor layer 1 on which an aluminum wiring 2 is formed, and is patterned and removed from the aluminum wiring 2 to form an opening. 5 is formed.

As shown in FIG. 1B, a diffusion preventing metal layer 3 made of titanium and having a thickness of 5000 mm and an adhesion strengthening metal layer 7 made of platinum and having a thickness of 5000 mm are sequentially laminated by sputtering. Next, a resist layer 15 is formed, and the resist layer 15 is patterned and removed from the region excluding the bump formation region. Then, the adhesion strengthening metal layer 7 is etched using aqua regia and removed from the region excluding the bump formation region. I do.

As shown in FIG. 1C, the resist layer 15 is removed to form a new resist layer 16, which is patterned and removed from the bump formation region to form an opening 10,
Gold plating is performed using the diffusion preventing metal layer 3 as a current path, and a bump 11 is formed in the opening 10.

As shown in FIG. 1D, the resist layer 16 is removed, and etching is performed using a mixed solution of ammonia and hydrogen peroxide with the adhesive metal layer 7 as a mask, thereby exposing the resist layer 16. The diffusion preventing metal layer 3 is removed.

[0007]

When the diffusion preventing metal layer 3 made of titanium is etched using the adhesion strengthening metal layer 7 made of platinum as a mask, the diffusion preventing metal layer 3 is formed by a battery effect between platinum and titanium. The aluminum wiring 2 is corroded or deteriorated due to the large side etching, and the etching liquid penetrates through the side etching.
The diffusion preventing metal layer 3 that should be present between the aluminum wiring 2 and the bump 11 disappears and loses the barrier property, and the reliability of the semiconductor device may be significantly reduced.

SUMMARY OF THE INVENTION An object of the present invention is to eliminate this drawback, and to prevent side-etching of the diffusion preventing metal layer to prevent corrosion and deterioration of the aluminum wiring, and to reduce the distance between the aluminum wiring and the bump. An object of the present invention is to provide a method for forming a bump which can surely maintain a barrier property.

[0009]

The above object is achieved by any of the following means.

[0010] The first means is to form a bump on a semiconductor layer.
A method of manufacturing a semiconductor device , comprising:
Forming a metal wiring and a laminate made of a diffusion preventing metal layer,
Forming an insulating film on the laminate and patterning the insulating film;
To remove from the laminate, and place a first opening on the laminate.
Forming an opening, and forming a port on the insulating film and the first opening;
It has substantially the same diffusion prevention effect as the diffusion prevention metal layer.
Forming a current path metal layer made of metal
Forming an adhesion-enhancing metal layer on the pass metal layer and strengthening the adhesion
Pattern the metal layer to remove the bump formation area.
The metal layer for the current path is removed
Forming a resist layer on the metal layer and the adhesion-enhancing metal layer
And patterning the resist layer to form a bump formation region.
Area of the resist layer is removed, and a second
2 and an electric current is applied to the current path metal layer.
Plating, and a bump is formed on the adhesion strengthening metal layer.
And forming the current through the adhesion-enhancing metal layer as a mask.
It is a method of manufacturing a semiconductor device including a step of removing a pass metal layer .

The second means is to form a bump on a semiconductor layer
A method of manufacturing a semiconductor device, comprising:
Forming a metal wiring, forming an insulating film on the metal wiring,
Pattern the insulating film and remove it from above the metal wiring
Forming a first opening on the metal wiring;
Forming a diffusion preventing metal layer on the first opening and the first opening;
The diffusion preventing metal layer is patterned to form the bumps.
Removing the diffusion preventing metal layer in the region excluding the formation region,
On the insulating film and the diffusion preventing metal layer, the diffusion preventing metal
Metals that have substantially the same anti-diffusion effect as the metal layer
Forming a current path metal layer, wherein said current path metal layer
Forming an adhesion reinforcing metal layer thereon, and patterning the adhesion reinforcing metal layer.
To remove the bump forming area
Removing the adhesion strengthening metal layer, the current path metal layer and the
Forming a resist layer on the adhesion-enhancing metal layer;
Patterning the resist layer and forming a resist in the region where the bump is to be formed.
Removing the layer to form a second opening over the adhesion enhancing metal layer;
By flowing a current through the current path metal layer.
Doing a stick, forming a bump on the adhesion strengthening metal layer,
The current path metal layer using the adhesion strengthening metal layer as a mask.
Is a method for manufacturing a semiconductor device having a step of removing a semiconductor device.

[0012]

Since the diffusion preventing metal layer is etched using the resist layer as a mask, side etching due to the battery effect is prevented, and the amount of side etching is reduced. If a large resist mask is formed in advance in consideration of the amount of side etching, it is easy to form a diffusion preventing metal layer in a desired shape.

Since the diffusion preventing metal layer 3 is patterned before the bumps are formed, the diffusion preventing metal layer 3 cannot be used as a current path for electroplating. As a countermeasure, a new current path metal layer 6 is formed. I did it. Since the current path metal layer 6 is used only for flowing a plating current, it can be formed extremely thin. Therefore, when the current path metal layer 6 is removed by etching using the adhesion strengthening metal layer 7 as a mask, the amount of side etching is extremely small. The problem that the layer 3 disappears and the barrier property is lost does not occur.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to the drawings, a method for forming a bump according to two embodiments of the present invention will be described below.

First Example FIG. 1 shows a process diagram for forming bumps.

As shown in FIG. 1A, an aluminum layer 2 having a thickness of 1 to 2 μm is formed on a semiconductor layer 1 by sputtering.
And a diffusion preventing metal layer 3 made of titanium having a thickness of 5000 mm are sequentially formed and then patterned to form a diffusion preventing metal layer 3.
The aluminum wiring 2 covered with is formed. Then PS
An insulating film such as G is formed, and is patterned to form a wiring 2
The opening 5 is formed by removing from above.

As shown in FIG. 1B, a current path metal layer 6 made of titanium and having a thickness of 100.degree.
And an adhesion strengthening metal layer 7 made of platinum having a thickness of 5000 mm are sequentially laminated. Next, a resist layer 8 is formed, and the resist layer 8 is patterned and removed from the region excluding the bump formation region. Then, etching is performed using aqua regia, and the adhesion reinforcing metal layer 7 is formed from the region excluding the bump formation region. Remove.

As shown in FIG. 1C, the resist layer 8 is removed, a new resist layer 9 is formed, and the resist layer 9 is patterned and removed from the bump formation region to form an opening 10. Next, gold plating is performed using the current path metal layer 6 as a current path, and a bump 11 is formed in the opening 10.

As shown in FIG. 1D, the resist layer 9 is removed, and etching is performed using the adhesion strengthening metal layer 7 as a mask and a mixed solution of ammonia and hydrogen peroxide as an etchant. The thin current path metal layer 6 is removed by etching.

Second Example FIG. 2 shows a process of forming bumps.

As shown in FIG. 1A, an aluminum wiring 2 is formed on a semiconductor layer 1. Next, an insulating film 4 such as PSG is formed, and is patterned and removed from the wiring 2 to form an opening 5.

As shown in FIG. 1B, a diffusion preventing metal layer 3 made of titanium and having a thickness of 5000 mm is formed by using a sputtering method. Next, a resist layer 12 is formed, and the resist layer 12 is patterned and removed from the region excluding the bump formation region, and then etched using a mixed solution of ammonia and hydrogen peroxide to remove the bump formation region. The diffusion preventing metal layer 3 is removed from the region.

As shown in FIG. 3C, the resist layer 12 is removed, and a current-pass metal layer 6 made of 100-mm thick titanium and a metal layer 7 made of platinum 5000 mm-thick are strengthened by a sputtering method. Are sequentially laminated. Next, a resist layer 13 is formed, and the resist layer 13 is patterned and removed from the region excluding the bump formation region. Then, etching is performed using aqua regia, and the adhesion reinforcing metal layer 7 is removed from the region excluding the bump formation region.
Is removed.

As shown in FIG. 1D, the resist layer 13 is removed, a new resist layer 14 is formed, and the resist layer 14 is patterned and removed from the bump formation region to form the opening 10. Next, gold plating is performed using the current path metal layer 6 as a current path, and a bump 11 is formed in the opening 10.

Next, although not shown, the thin metal layer for current path 6 having a thickness of 100 mm is removed by etching using the adhesion strengthening metal layer 7 as a mask, as in the first example.

[0026]

As described above, in the method of manufacturing a semiconductor device according to the present invention, when a bump is formed by using an electrolytic plating method, a diffusion preventing metal layer formed between a wiring and a bump is formed. Since the etching is performed using the resist layer as a mask, side etching of the diffusion preventing metal layer due to the battery effect is prevented. On the other hand, since the current path metal layer separately formed as a current path at the time of forming a bump is formed extremely thin, side etching at the time of etching the current path metal layer is extremely slight,
Prevents the wiring from being corroded or deteriorated by the intrusion of the etchant, and the diffusion prevention metal layer from disappearing.
The reliability of the semiconductor device is significantly improved.

[Brief description of the drawings]

FIG. 1 is a diagram showing a bump forming process according to a first embodiment of the present invention.

FIG. 2 is a view showing a bump forming process according to a second embodiment of the present invention.

FIG. 3 is a view showing a conventional bump forming process.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Semiconductor layer 2 Metal wiring 3 Diffusion prevention metal layer 4 Insulating film 5 Opening 6 Metal layer for current path 7 Adhesion strengthening metal layer 10 Opening 11 Bump

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H01L 21/60

Claims (2)

(57) [Claims] (1)A semiconductor device for forming a bump on a semiconductor layer
Manufacturing method of the,A product comprising a metal wiring and a diffusion preventing metal layer on the semiconductor layer
Forming a layered body, Forming an insulating film on the laminate and patterning the insulating film;
To remove from the laminate, and place a first opening on the laminate.
Form the mouth, The diffusion preventing gold is formed on the insulating film and the first opening.
Metals that have substantially the same anti-diffusion effect as the metal layer
Forming a current path metal layer, Forming an adhesion reinforcing metal layer on the current path metal layer,
Forming the bumps by patterning the adhesion-enhancing metal layer
Removing the adhesion-enhancing metal layer in a region excluding the region, The metal layer for the current path and the adhesion reinforcing metal layer
Forming a dist layer, patterning the resist layer,
By removing the resist layer in the area where the bumps are formed,
Forming a second opening on the metal oxide layer, The plating is performed by passing a current through the current path metal layer.
Performing, forming a bump on the adhesion strengthening metal layer, The current path metal layer using the adhesion strengthening metal layer as a mask.
Remove A method for manufacturing a semiconductor device, comprising: (2)A semiconductor device for forming a bump on a semiconductor layer
A method of manufacturing the device, Forming a metal wiring on the semiconductor layer, An insulating film is formed on the metal wiring, and the insulating film is patterned
To remove from the metal wiring,
Forming a first opening, A diffusion preventing metal layer on the insulating film and the first opening;
Is formed, and the diffusion preventing metal layer is patterned,
Excluding the diffusion preventing metal layer in the region except the bump formation region
Leave The diffusion barrier is formed on the insulating film and the diffusion barrier metal layer.
A metal having substantially the same diffusion prevention effect as the metal barrier layer
Forming a current path metal layer comprising:
Forming an adhesion strengthening metal layer on the metal layer,
Patterning The area other than the bump formation area
Removing the adhesion reinforcing metal layer, The metal layer for the current path and the adhesion reinforcing metal layer
Forming a dist layer, patterning the resist layer,
By removing the resist layer in the area where the bumps are formed,
Forming a second opening on the metal oxide layer, The plating is performed by passing a current through the current path metal layer.
Performing, forming a bump on the adhesion strengthening metal layer, The current path metal layer using the adhesion strengthening metal layer as a mask.
Remove A method for manufacturing a semiconductor device, comprising: