JPH0226029A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To avoid corrosion of a conductive layer by a method wherein, after the conductive layer is formed, a plasma discharge treatment with gas containing carbon and fluorine is performed to form an organic molecule film and a protective film is applied to it. CONSTITUTION:An Al film is formed so as to cover a silicon oxide film 2 formed on a silicon substrate 1 and dry-etching is performed with a photoresist film 4 as a mask to form an Al wiring 3 as a conductive layer. After the Al wiring 3 is formed, a plasma treatment employing, for instance, CF4 or CHF3 gas is carried out to cover the Al wiring 3 with an organic molecule film 5 and a protective film 6 is formed on it. With this constitution, the corrosion of the conductive film 3 can be avoided and the reliability of a semiconductor device can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method for manufacturing a semiconductor device, and particularly to a method for forming wiring.

2. Description of the Related Art A2 alloy is generally used as a wiring material for semiconductor devices. Then, a passivation film is formed on the β alloy to protect the element.

As an example of a conventional semiconductor device manufacturing method, the manufacturing process of an MO8 type semiconductor device will be described with reference to FIGS. 2(a) to 2(C). Note that FIG. 2 shows the steps from the Aρ wiring formation process to the passivation film formation process, and for the sake of simplicity,
Transistor regions are not shown.

As shown in FIG. 2(a), first, a silicon oxide film 2 is formed on a circuit element (not shown) on a silicon substrate 1.
An Aρ film is further formed to cover the Aρ film, and this /l film is dry-etched using the photoresist 4 as a mask, thereby forming a λ pattern [13]. For example, a gas such as 8Cflx or Cj22 is used for this dry etching. Subsequently, as shown in FIG. 2(b), o2
After the photoresist 4 is removed by plasma, a ρ sintering process is performed, for example, in an N2/H2 mixed gas atmosphere at 450°C. Next, as shown in FIG. 2(C), a silicon nitride film 6 as a passivation film is formed by Si
It is formed by plasma discharge treatment using H4/N)+3 mixed gas. After this, the silicon nitride film 6 on the bonding pad is opened and completed.

Problems to be Solved by the Invention However, in the semiconductor device manufacturing method performed in this manner, the step coverage of the silicon nitride film 6 deteriorates in areas where the distance between the AA wirings 3 is narrow, and cracks 7 occur. Easy to occur. If a crack 7 occurs in the silicon nitride pattern 6, a serious problem arises in that moisture and impurities enter the semiconductor device from the outside during use, corroding the ohm wiring 3 and causing disconnection.

The present invention solves the above-mentioned problem, and aims to provide a method for manufacturing a semiconductor device in which even if cracks occur in the silicon nitride film 6, the ρ wiring 83 will not corrode and disconnect. .

Means for Solving the Problems In order to solve the above problems, the present invention provides that after forming a conductive layer, C
and F-containing gases such as CF4 or CHF
By applying plasma treatment using I gas,
The structure is such that a four-electrode layer is covered with an organic molecular film, and a protective film is applied on top of the organic molecular film.

Effect With the above configuration, even if moisture or impurities penetrate through the passivation film, which is a protective film, they will not penetrate into the conductive layer.
Since the wiring is covered with the organic molecule film, corrosion of the conductive layer can be prevented and the reliability of the semiconductor device can be improved.

Example An embodiment of the present invention will be described below based on the drawings.

FIG. 1 is a step-by-step sectional view of a method for manufacturing a semiconductor device showing an embodiment of the present invention, and will be explained using this. In addition,
For the sake of simplicity, the transistor region is intentionally not shown.

As shown in FIG. 1(a), first, a silicon oxide film 2 is formed on a circuit element (not shown) on a silicon substrate 1.
A ρ pattern is formed to further cover the AAH, and the AAH is dry-etched using the photoresist 4 as a mask, thereby forming the Aρ wiring 3. For this dry etching, for example, a mixed gas of 8 CΩ3/CΩ2/N2 is used. Subsequently, as shown in FIG. 1(b), after removing the photoresist 4 by 02 plasma treatment, Aρ
Perform training. Next, as shown in FIG. 1(C), plasma treatment using, for example, CF4 gas is performed,
An organic molecular film 5 is grown on the top surface and sidewalls of the Aρ wiring 3. Thereafter, as shown in FIG. 1(d), a silicon nitride film 6 is formed as a passivation film by plasma CVD using a 5in4/NH3 mixed gas. The heat treatment temperature at this time is about 300°C, but the organic molecule W
! 5 does not disassemble. Subsequently, the silicon nitride film 6 on the bonding pad is completed.

As a result of analysis, it was found that the main constituent elements of the organic molecular film 5 were carbon (C) and fluorine (F). Although CF4 gas was used to form the organic molecular film in this example, similar effects can be expected by using other gases containing C and F.

Next, an example thereof will be explained. Model thickness 0.8 μm.

Line width 1.8μm, line spacing 1.8μm, length 6x101
When an accelerated field test (temperature 85°C, relative humidity 85%, test time 1000 hours) was conducted using μm Aj2-1wt%S i -0.5wt%Cu wiring pattern, it was found that in the case of this example The Ω disconnection defect rate is 2 compared to the conventional example.
It was 0%. Note that in both cases, a silicon nitride film with a thickness of 0.5 μm was used as the passivation film.

Effects of the Invention As described above, according to the present invention, the organic molecular film
It acts as a barrier to the reaction between the metal and the infiltrated water, thus preventing corrosion of the conductive layer.

[Brief explanation of the drawing]

FIGS. 1(a) to (d) are cross-sectional views showing the manufacturing process of an embodiment of the present invention, and FIGS. 2(a) to (C) are cross-sectional views showing the conventional manufacturing process. 1... Silicon substrate, 2... Silicon oxide film, 3...
・AI2 wiring (conductive layer), 5... organic molecular film, 6...
・Silicon nitride l1l (passivation film, protective film)
. Agent Hiroshi Tsuru Morimoto Figure 2

Claims (1)

[Claims] 1. After forming a conductive layer on a semiconductor substrate directly or via an intermediate layer, the conductive layer is subjected to plasma discharge treatment using a gas containing carbon and fluorine, and organic molecules are formed on the upper surface and side surfaces of the conductive layer. A method for manufacturing semiconductor devices that involves forming a film and applying a protective film on top of it.