JPH0555218A - Semiconductor device and manufacture thereof - Google Patents

Abstract

PURPOSE:To reduce the generation of corrosion, and to enable aluminum alloy wiring machining having high accuracy by inserting a dummy pattern into an open space. CONSTITUTION:An aluminum alloy film 5 as an aluminum alloy wiring is formed onto a foundation substrate 2 through sputtering, vacuum deposition or the like. The aluminum alloy film 5 is patterned while using a positive resist as a mask through photoengraving so as to be patterned as the aluminum alloy wiring. The aluminum alloy film 5 is etched by using a patterned resist mask. The film 5 is etched, the resist mask is ashed by employing chlorine group gas by a barrel type and a downflow type asher, and a resist is removed. The sidewall deposit film 7 of the aluminum alloy wiring is removed through the wet etching of a resist peeling liquid, etc. A sidewall deposit film 7a after etching is thinned by forming a dummy pattern 10 in a wide open space, and a residual chlorine section is reduced, thus inhibiting the generation of corrosion.

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 method of forming an aluminum alloy pattern used for electrode wiring of a semiconductor device.

[0002]

2. Description of the Related Art FIG. 3 schematically shows a conventional method for forming an aluminum alloy electrode wiring. FIG. 3A shows a process of forming an aluminum alloy film 5 to be an aluminum alloy wiring on the base substrate 2 by sputtering or vacuum deposition.
(b) shows a step of patterning by photolithography using, for example, a positive resist as a mask for patterning as aluminum alloy wiring. FIG. 3C shows a step of etching the aluminum alloy film using the patterned resist mask. Etching is usually performed by RIE (Reactive Ion Etching) or magnetron RIE for fine patterns.
Is used. A chlorine-based gas, for example, a mixed gas of SiCl ₄ / Cl ₂ or the like is used as the etching gas. FIG. 3 (d) shows a state immediately after the resist mask is ashed by oxygen-based gas with a barrel type or downflow type asher after etching the aluminum alloy wiring of FIG. 3 (c). There is. 3 (e) is generated in the etching process of FIG. 3 (c) after the ashing process of FIG. 3 (d) by the process flow 3 (f) described below due to moisture or chlorine atmosphere in the atmosphere. It is a figure which shows that corrosion 9 generate | occur | produces from the deposited film 7 of the side wall.

In particular, the corrosion 9 is highly likely to occur from the side wall 7b of the aluminum alloy wiring facing the open space 8.
FIG. 3F shows a step of removing the side wall deposited film 7 of the aluminum alloy wiring generated in the etching step of FIG. 3C by wet etching with a resist stripping solution or the like. In this case, the corrosion 9 is generated from the aluminum alloy and is not removed by wet etching with a resist stripping solution or the like. Even if corrosion 9 does not occur in the process of FIG. 3 (e), it occurs during or after the resist stripping solution treatment.

In the conventional patterning of the aluminum alloy wiring 11, as shown in FIG. 4, the film 7 deposited on the side wall according to the size of the open space width w _n facing the aluminum alloy wiring 11.
Are different. The reason is that the solid angle attached to the side wall differs depending on the open space 8. Therefore, when the open space width is w ₁ <w ₂ <w ₃ , as shown in FIG. Solid angle is θ ₁ <θ ₂
<Theta _3, and the film thickness to be deposited on the side wall in this order, the film quality becomes different.

When chlorine-based gas SiCl ₄ / Cl ₂ is used as an etching gas, the components deposited on the sidewalls are composed of Al, Cl, Si, and Al _x Cl _y Si _z (x, y, The occurrence of corrosion differs depending on the composition ratio (z: composition ratio) and the residual concentration of Cl. Usually, the side wall facing the open space of 5 μm or more has a large amount of residual chlorine and is easily corroded. Also, corrosion 9
The occurrence of the short circuit may cause a short circuit between the wirings, leading to a decrease in the reliability of the device.

[0006]

In the conventional method for forming an aluminum alloy film pattern, the deposits produced during etching of the aluminum alloy adhere to the side wall 7b of the aluminum alloy wiring facing the open space thickly to prevent the occurrence of corrosion. It was high. Therefore, in the etching process for thinning the deposited film, the amount of deposition of the aluminum alloy wiring side wall 7a facing a narrow space is reduced, the side wall protection effect at the time of aluminum alloy etching is weakened, and the etching shape is affected. There was a point.

The present invention has been made in order to solve the above-mentioned problems. It is possible to reduce the occurrence of corrosion, anisotropically etch the shape of aluminum alloy wiring, and further, to make a difference in mask pattern. It is an object of the present invention to obtain a semiconductor device and a method for manufacturing the same, which can reduce the dependency on the area to be etched due to.

[0008]

According to the present invention, there is provided a semiconductor device and a method for manufacturing the same, in a photolithography process for etching an aluminum alloy, the aluminum alloy is provided in a wide open space of at least 5 .mu.m or more for increasing the rate of corrosion. A dummy pattern is inserted and etching is performed.

[0009]

In the present invention, the dummy pattern reduces the deposit on the side wall of the aluminum alloy wiring and also reduces the difference in the deposited film thickness on the side wall due to the difference in the open space size. Further, since the area to be etched is greatly reduced by inserting the dummy pattern, the mask pattern dependency is reduced and the etching rate is also improved.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows aluminum alloy wiring patterning in which a dummy pattern 1b is provided in a place 4 which was a large space in order to prevent corrosion in a semiconductor device and a manufacturing method thereof according to an embodiment of the present invention. FIG. 2 is a diagram schematically showing the forming method of FIG. FIG. 2A shows a step of forming an aluminum alloy film 5 to be an aluminum alloy wiring on the base substrate 2 by sputtering or vacuum deposition. Figure 2 (b)
Shows a step of patterning by photolithography using, for example, a positive resist as a mask for patterning as aluminum alloy wiring. In this resist patterning, originally, the resist is patterned also in a wide open space (25 μm) where there is no resist mask for wiring.

FIG. 2C is a diagram showing a step of etching the aluminum alloy film 5 using a patterned resist mask. Etching is usually RI for fine patterns.
E or magnetron RIE is used. A chlorine-based gas, for example, a mixed gas of SiCl ₄ / Cl ₂ or the like is used as the etching gas. FIG. 2D shows a state immediately after the resist mask is ashed by chlorine-based gas using a barrel type or downflow type asher after etching the aluminum alloy wiring. Figure 2 (e) shows
After the ashing process, the process shown in FIG.
It is shown that corrosion does not occur from the deposited film 7 on the side wall generated in the etching step of (c) or the occurrence rate is reduced.
FIG. 2F is a diagram showing a step of removing the side wall deposited film 7 of the aluminum alloy wiring formed in the etching step by wet etching with a resist stripping solution or the like. In this case, since the deposited film 7 on the side wall, which is the cause of aluminum corrosion, is removed, the occurrence of corrosion is further suppressed.

In the steps shown in FIGS. 2B and 2C, by forming the dummy pattern 10 in a wide open space, the side wall deposited film 7a of the aluminum alloy wiring 11 and the aluminum alloy dummy pattern 12 after etching is thin. Therefore, the residual chlorine content is reduced, and the occurrence of corrosion is suppressed.
The thin side wall deposited film is due to the incident solid angle shown in FIG. By reducing the occurrence of this corrosion, the problem of short circuit between wirings is also reduced, and the reliability of the device is improved.

Although SiCl ₄ / Cl ₂ is used as the etching gas in the above embodiment, BCl ₃ , BBr ₃ ,
Even if CF ₄ or N ₂ is used or mixed with Cl ₂ , the same effect as that of the above-described embodiment can be obtained.

Further, in the above-mentioned embodiment, the positive type is used for the resist, but even if the negative type is used, if the mask pattern is reversed, the same effect as that of the above-mentioned embodiment is obtained.

[0015]

As described above, according to the present invention, since the dummy pattern is inserted in the open space, it is possible to reduce the occurrence of corrosion and perform highly accurate aluminum alloy wiring processing.

Further, by inserting the dummy pattern, the area to be etched is reduced, the mask pattern dependence is reduced, and the etching characteristics can be stabilized.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a semiconductor device and a manufacturing method thereof according to an embodiment of the present invention.

FIG. 2 is a diagram showing an aluminum alloy pattern forming flow according to the present invention.

FIG. 3 is a diagram showing a flow of forming a conventional aluminum alloy wiring.

FIG. 4 is a diagram showing a relationship between a space size facing a side wall and an incident solid angle.

[Explanation of symbols]

1 Aluminum Alloy Wiring Electrode 1a Wiring Required for Operation 1b Dummy Pattern 2 Base Substrate 3 Sidewalls where Corrosion Easily Occurs 4 Space Without Aluminum Alloy Wiring 5 Aluminum Alloy Film 6 Aluminum Alloy Wiring Resist Pattern 7 Sidewall Deposited Film 7a Narrow Sidewall deposited film facing a space 7b Sidewall deposited film facing a wide space 8 Wide space 9 Corrosion 10 Dummy pattern resist pattern 11 Aluminum alloy wiring 12 Aluminum alloy dummy pattern 13 Shorting location θ ₁ Aluminum alloy wiring Sidewall Can be deposited at point A Incident solid angle θ ₂ incident solid angle that can be deposited on the aluminum alloy wiring side wall point B θ ₃ incident solid angle that can be deposited on the aluminum alloy wiring side wall point c _n wiring spacing (w ₁ <w ₂ <w ₃ )

Claims (2)

[Claims] 1. A semiconductor device comprising: an aluminum alloy wiring pattern having an open space of 5 μm or more; and a dummy aluminum alloy pattern provided in the open space of the aluminum alloy wiring pattern. 2. A method of manufacturing a semiconductor device, comprising: a step of forming an aluminum alloy wiring pattern having an open space of 5 μm or more; and a step of forming a dummy aluminum alloy pattern in the open space.