JPS6180824A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To prevent generation of the short-circuit between metals such as Al and the like and the contact of the Al and the like and a metal etchant by a method wherein, after the metal such as Al and the like located on a photoresist is completely removed, the exposed photoresist is removed. CONSTITUTION:The pattern of a photoresist 2 is formed on a silicon substrate 1 using a photolithographic technique, and Al 3 is adhered on the whole surface by performing a vacuum evaporation method and the like. Subsequently, a photoresist film 4 is coated by performing a spin-on method and the like. Then, an etching is performed on the photoresist 4 until the surface of the Al 3 is exposed by performing a dry etching and the like using CF4 gas. The exposed Al 3 is etched using a phosphoric acid and the like, and lastly, the photoresists 2 and 4 are completely removed using a parting liquid and the like.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for manufacturing semiconductor devices such as integrated circuits, and in particular to a method for patterning aluminum or other metals using photolithography technology such as electrodes. .

[Conventional technology]

Conventionally, as a fine patterning method for metals such as At,
■Lift-off method, ■Chemical etch method are used. Meng will explain these below.

(2) Lift-off method As shown in FIG. 3, a pattern of photoresist 2 is formed on silicon substrate 1 by photolithography (FIG. A). Next C:, On this (:, Attach metal 5 such as At to the entire surface by vacuum evaporation method etc. (Figure B)
. Next, remove the photoresist 2 using a resist stripper or the like.
At the same time, metal 3 such as At on the photoresist film is also removed.

As a result, the metal 3 such as At has a desired pattern as shown in FIG.

However, as shown in FIG. 4, the metal 5 such as At may completely cover the photoresist 2, and in this case, the photoresist film does not melt with the photoresist removal solution, so the photoresist 2 Complete removal may not be possible in some cases, and there is a drawback that short circuits tend to occur between metals such as At.

■Chemical etching method As shown in Figure 2, first, a metal 3 such as At is deposited on the entire surface of the silicon substrate 1 (Figure A) by vacuum evaporation.
. Next, a pattern of photoresist 2 is formed using photolithography technique 1 (Figure B). Next, the exposed portion of the metal 3 such as At is chemically etched (Quette etch or CCt using phosphoric acid, etc.).

Dry etching with gas etc.) (Remove from the second step (Figure C)
o Finally (=, remove the photoresist 2 and obtain the desired pattern of the metal 3 such as At (Figure D).

However, as shown in FIG. 5, if the etching time is too long, the metal 5 such as At directly under the photoresist 2
Also, the side is fucked. Therefore, with chemical etching methods, it is difficult to control etching, and excessive etching can lead to A.
The line width of I, etc. becomes thinner, and not only is it impossible to obtain the desired width, but in severe cases, the metal, such as At, becomes disconnected.

[Problems to be Solved by the Invention] The present invention aims to eliminate the drawbacks of the above-mentioned lift-off method and chemical etching method, and to enable fine processing of metals such as At.

[Means for solving problems]

In the present invention, the manufacturing process of an integrated circuit made of silicon or the like includes the following steps 1 to 2.

(2) A first photoresist pattern is formed on the silicon substrate by photolithography.

(2) On top of that, a metal such as At is deposited on the entire surface by vacuum evaporation method or the like.

@Sarah L: Furthermore, a second photoresist film is applied using a spin-off method or the like so that the surface is almost flat.

(2) This photoresist film is etched until the surface of the metal such as At is exposed.

■ Process the metals such as At exposed in ■ with phosphoric acid etc. 1
Tsutengu.

Finally, all the photoresist film is removed and the desired A1
etc. to obtain metal patterns.

[Effect]

In the present invention, the metal such as At on the photoresist is first completely removed, and then the exposed photoresist is removed. There is almost no chance of it remaining.

Furthermore, since the metal such as At which should remain on the silicon substrate is surrounded by the carbon photoresist on both upper sides, it does not come into contact with the etchant for the metal such as aluminum. Therefore, the phenomenon of excessive etching, which is a problem in chemical etching methods, cannot occur.

〔Example〕

In Figure 1, a pattern of photoresist 2 is formed on the silicon substrate 1 in Figure A by photolithography, and in Figure B, a pattern of A1 is formed on the entire surface by vacuum evaporation.
Attach 3. Subsequently, in FIG. C, a photoresist film 4 is applied by a spin-on method or the like. At this time, it is desirable that the surface of the photoresist film 4 be flat. Next, photon cysts 4 are etched in A1 by a dry etching method using CF, gas, etc. in Figure D (2).
Etch until surface 5 is exposed. Next, there is 3 in figure E and exposed A15 '2! Etch using phosphoric acid, etc. Finally, as shown in FIG.

Although the embodiments have been disclosed above using two alloys, the present invention can be widely applied to various other metals used in semiconductor devices such as silicon integrated circuits, such as Mo, W, Ata, etc.

〔Effect of the invention〕

According to the present invention (2), A on photoresist as described above
1st grade metal 3 First, remove the photoresist and the At attached on the photoresist in order to remove the exposed photoresist.
Since metals such as At do not remain, there is no risk of short circuit between metals such as At. In addition, metals such as At that should be left on both sides of the upper part (surrounded and protected by niphoresist, do not come into contact with etchants such as At, and avoid the excessive etching phenomenon that is a problem with the chemical etching method). Therefore, the drawbacks of chemical etching methods, such as narrowing the line width of metal such as At or breaking the wire in the worst case, do not occur.As a result of the above, the present invention (according to This will greatly benefit the manufacture of 1,400-unit devices such as integrated circuits.

[Brief explanation of drawings]

Figures 1A-F are process diagrams of an embodiment of the present invention, Figure 21V
A-D is a process diagram of the conventional chemical etching method, FIG. 5 A-C is a process diagram of the conventional lit-off method, and FIGS. 4 and 5 are disadvantages of the conventional lift-off method and chemical etching method, respectively. This is an explanatory diagram. 1...Silicon substrate

Claims (1)

[Claims] A step of forming a first photoresist pattern on the semiconductor substrate by photolithography technology, a step of forming a metal layer on the entire surface of the semiconductor substrate including the photoresist pattern, and a step of forming a second photoresist film on the upper surface. a step of etching the second photoresist film until the surface of the metal layer is exposed; a step of etching and removing the exposed metal layer; A method for manufacturing a semiconductor device, comprising the steps of: removing all of the second photoresist film.