JPS6384048A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To eliminate the need for etching by a chloride and remove a residual chloride, and to reduce a stepped section at the time of multilayer interconnections and prevent disconnection by changing sections functioning as no wiring in conductive films into insulators. CONSTITUTION:An SiO2 film 17 and an Al film 18 are formed onto a semicon ductor substrate 16, and Ar ions are implanted, using resist patterns 191, 192 as masks. Consequently, since sections 21a-21c not masked are brought to an amorphous state, the sections 21a-21c are converted into Al(OH)3 when the whole is dipped in pure water after removing a resist. When the whole is heated in an H2+N2 atmosphere, Al(OH)3 is dehydrated, and turned into Al2O3. Since Al2O3 is an insulator, wiring patterns 181 and 182 can be insulated and isolated. An SiO2 film 22 is shaped onto a wiring layer. Since the wiring patterns and the insulator are formed onto the same plane, the film 22 is also flattened, thus generating no disconnection even on multilayer interconnections.

Description

DETAILED DESCRIPTION OF THE INVENTION [Purpose of the Invention (Industrial Application Field) The present invention relates to a method for manufacturing a semiconductor device, and particularly relates to the formation of wiring.

(Prior Art) Generally, a wiring process in a semiconductor device is performed as shown in FIGS. 2(a) to 2(f), for example. First, an insulating g! A conductive film 13, which will become a wiring, is formed on the insulator 1!112 (FIG. (B)). Next, a resist 14 is applied onto the conductive film 13, and the resist is selectively removed by photolithography to form predetermined resist patterns 141 and 142 (FIG. 1C).

After that, the patterned resist 141°14
2 as a mask, the conductive wA13 is selectively removed, and the wiring pattern 13. , 132 (Figure (d)). Next, the resist patterns 141 and 142 are removed (see (e)). Finally, an insulating film 15 is formed on the wiring patterns 131 and 132 formed above (
(f) Figure).

By the way, aluminum is currently widely used as the conductive l113 (wiring material). When this aluminum is microfabricated, a reactive ion etching method is used.

However, at this time, chlorinated methane (CH
Since a chlorine-based gas such as 4rLC (In n-1 to 4) is used, a small number of chloride ions remaining after etching corrode the aluminum, which is the wiring material, and the wiring will break during long-term use. There is a problem. Therefore, the reliability of the semiconductor device decreases.

Further, as shown in FIG. 2(f), the wiring pattern 13
The insulating film 15 on 1 and 132 has extremely poor flatness reflecting the unevenness of the underlying wiring pattern. Therefore, when a second layer wiring pattern is formed on the insulation 1!115, a problem arises in that the wiring is disconnected at the stepped portion. In order to eliminate such defects, after the step shown in FIG. A planarization process using Qn Glass) or the like is required. This makes the manufacturing process more complicated and
There is a drawback that the yield is also reduced.

(Problems to be Solved by the Invention) As described above, the conventional method of manufacturing a semiconductor device has the drawback that the wiring material is corroded by chloride left during etching, resulting in disconnection of the wiring.

In addition, when performing multilayer wiring, the wiring is likely to break at the step part of the wiring pattern, and a flattening process is required to prevent the breakage, which has the disadvantage of complicating the manufacturing process and lowering the yield. be.

This invention was made in view of the above-mentioned circumstances, and its purpose is to eliminate the risk of wire breakage caused by chloride remaining during etching, and to eliminate the risk of wire breakage that occurs during multilayer wiring without performing a planarization process. It is an object of the present invention to provide a method for manufacturing a semiconductor device that can prevent wire breakage, has high reliability, simplifies the manufacturing process, and has a high yield.

[Structure of the Invention] (Means and Effects for Solving the Problems) In order to achieve the above object, in this invention, an insulating film is formed on a semiconductor substrate, and a conductive film serving as wiring is formed on the insulating film. After forming the conductive film, a wiring pattern is formed using a resist on the conductive film, and using this resist as a mask, ions are implanted into the conductive film to form an amorphous part of the conductive film that will not become a wiring. become After removing the resist, the amorphous portion of the conductive film is converted into an insulator.

Thereby, the conductive film can be divided into a conductive part (wiring pattern) and an insulating part, and each wiring pattern can be electrically isolated. Moreover, since the wiring part and the insulator part are formed on the same plane, unevenness due to the wiring pattern is not formed, and the two
If a layered wiring pattern is formed, a planarization process is not necessary, and the manufacturing process can be simplified.

(Example) Hereinafter, an actual example of the present invention will be described with reference to the drawings. FIGS. 1(a) to 1(f) focus on the wiring process of a semiconductor device. First, a first
As an insulating film, a SiO2 film 17 is deposited to a thickness of, for example, 3,000 g4 by a typical vapor phase growth method (Figure (a)). Next, an aluminum film 18 is formed as a conductive film on the 5iO2 1117 by sputtering to a thickness of, for example, 4,000 mm (FIG. 3(b)). Thereafter, a resist 19 is applied onto the aluminum film 18, and predetermined resist patterns 191 and 192 are patterned by photolithographic etching (FIG. 1C). Next, using the patterned resists 191 and 192 as masks, argon Ar ions are added to the aluminum 1118 at an acceleration voltage of 50 KeV and a dose of 15X1Q l 60 m.
4 (Figure (d)).

After this, the resist 19. , 192 are removed. By the ion implantation of argon, the aluminum 1
418 of the above resist 19. , 192 patterns, the portions 18a, 18b, and 18c that were not masked are made amorphous (FIG. (e)). Next, when the semiconductor substrate 16 is soaked in pure water at 80° C. for 5 minutes, the amorphous aluminum films 18a, 18b, 18G react with water to form aluminum hydroxide films 20a, 20b.

20G (Figure (f)). This reaction is expressed by the following formula (1)%
Formula % A℃+3H20-+Aj2 (OH)3 +3/2
H2... (1) During the above reaction, the reaction rate of the aluminum film 18 that has not been made amorphous is extremely slow, and hardly turns into aluminum hydroxide. The reaction rate is 800 people/min for amorphous aluminum j120a, 20b, and 20c, and 80 people/min for aluminum B118.

Next, the semiconductor substrate 16 is heated to 82 + at 450°C, for example.
When heated for 30 minutes in a N2 atmosphere, the aluminum hydroxides g120a, 20b, and 20c are dehydrated to become aluminum oxides 1121a, 21b, and 21c. This reaction is shown in the following formula (2).

2Ag (OH)3-+Affi203 +3H20↑
(2) The aluminum oxide films 21a, 21b, 21c are insulators, and aluminum g! 18 wiring patterns 18° and 182 can be electrically separated (Figure (g)). Next is the above aluminum! ! 118 wiring pattern 181°18
2, an S+02 film 22 is deposited as a second insulating film to a thickness of about 3000 by chemical vapor deposition (((
h) Figure).

According to such a manufacturing method, in the past, the wiring pattern was formed by removing unnecessary conductive films by etching, but in the present invention, the wiring pattern is formed by changing unnecessary parts of the wiring to an insulating material. , so there is no need to perform etching. Therefore, the wiring material is not corroded by the chlorides left during etching, and there is no fear that the wiring will be disconnected. Therefore, reliability of the semiconductor device can be improved.

In addition, S i 02 n22 in the process shown in 1) above
A second WJ aluminum film is formed on top, and the above (C)
Multilayer wiring can be formed by repeating the steps shown in FIGS. In this case, since the wiring pattern and the insulator for electrically isolating the wiring pattern are formed on the same plane, the level difference is extremely small and the surface flatness is excellent. Therefore, there is no need to perform a planarization process using an etch-back method or SOG, which greatly simplifies the manufacturing process and improves yield.

Note that in the above embodiment, the first. An 8i02 film made by chemical vapor deposition was used as the second insulating film, but PSG, BP
SG, Si3N4, SiC, etc. may also be used.

Furthermore, although argon ions were implanted into the aluminum film 18 to make it amorphous, He.

Ions such as Ne, Kr, O, or N may also be used.

Further, this aluminum film contains Sl.

Elements such as Cu and Pd may be added.

[Effects of the Invention] As explained above, according to the present invention, there is no fear of wire breakage due to chloride remaining during etching, and wire breakage that occurs during multilayer wiring can be prevented without performing a planarization process.
A method for manufacturing a semiconductor device that is highly reliable, simplifies the manufacturing process, and has a high yield can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a diagram for explaining a method for manufacturing a semiconductor device according to an embodiment of the present invention, and FIG. 2 is a diagram for explaining a conventional method for manufacturing a semiconductor device. 16... Semiconductor substrate, 17... SiO2 film (first insulating film), 18... Aluminum film (conductive II,
18a. 18b, 18c...Amorphous aluminum film,
181°182...Wiring pattern, 19...Resist, 21a, 21b. 21c...aluminum oxide film, 22...5iO2
Ii! J (second insulating film).

Claims (1)

[Claims] A step of forming a first insulating film on a semiconductor substrate, a step of forming a conductive film on this insulating film, a step of applying a resist on this conductive film, and a step of patterning this resist. , a step of selectively amorphizing the conductive film by performing ion implantation using the patterned resist as a mask, and a step of removing the resist;
forming a wiring pattern by electrically separating the non-amorphous portion of the conductive film by converting the amorphous conductive film into an insulator; and forming a wiring pattern on the conductive film. 2. A method of manufacturing a semiconductor device, comprising the step of forming an insulating film.