JPS6376874A - Vapor growth method - Google Patents

Abstract

PURPOSE:To form a thin film contg. Si in Al with high controllability by CVD by using org. and inorg. Al compds. as source gases and feeding them to a chamber together with H2. CONSTITUTION:An org. Al compd. such as TIBA, TMA or TEA and an inorg. Al compd. such as TSA or TDSA used as source gases are fed to a chamber 11 together with gaseous H2 and blown on a substrate 12 to grow a thin Al-Si film on the substrate 12 at about 260-360 deg.C. The chamber 11 is evacuated beforehand to about 0.5-1.5Torr degree of vacuum and the flow rate of the org. and inorg. Al compds. is regulated to about 1-10cc/min. By this method, the amount of Si in the thin film can be changed with high controllability and the adhesion of the stepped part is improved.

Description

[Detailed Description of the Invention] [Summary] Using organic and inorganic aluminum as a source gas,
1-A Si alloy thin film is formed.

[Industrial application field]

The present invention relates to a vapor phase growth method, and more specifically, to forming a thin film of an aluminum silicon (A6-5i) alloy by chemical vapor deposition (CVD), in which silicon is contained in aluminum with good controllability. It's about how to do it.

[Conventional technology]

Wiring of a semiconductor device is generally formed by patterning an A1 film made by growing A2 using the CVO method. For CVD growth of AN, for example, triisobutylaluminum (t
riisobutyl aluminum, TIBA
+ Aff (1so-C or H2)3) is used as a source gas.
R) 3-TMA [(trimethylaluminum),
i (C113) 3), triethylaluminum (AJ CCIH5) 3, TEA 3, etc.

[Problem that the invention seeks to solve]

When wiring is formed with pure aluminum formed using the organic aluminum described above, electromigration (electron migration) and stress or thermal migration (st
ress or thermal IImigrati
It was confirmed that there is a risk of wire breakage due to In electromigration silane, when a current is passed through the Al wiring, electrons collide with the Al atoms, and this physical impact causes the atoms to move and form a thin part in the Al wiring, which is heated by Joule heat. disconnected by. Stress or thermal migration is caused by the heat generated when a protective film or the like is grown on the Al wiring, and stress is generated between the protective film material having a different thermal expansion coefficient and the Al wiring, and this stress causes the Af wiring to be cut.

Therefore, approximately 1% silicon (Si) is added to Al.

Attempts have been made to solve the above-mentioned problems by incorporating w4 (Cu), etc., but it is difficult to incorporate silicon into Al with good controllability.

The present invention was created in view of these points, and
The purpose of the present invention is to provide a method for containing silicon in nitrogen with good controllability in CVD growth.

[Means for solving problems]

FIG. 1 is a sectional view of an embodiment of the present invention, in which 11 is a chamber, 12 is a substrate, 13 is a susceptor, 14 is a heater, 15
1 is an exhaust pipe, and 16 is a gas supply section.

In the present invention, the source gas is organic aluminum + inorganic aluminum, such as trisilyaluminum (T
S^, Al (5iH3)) is used and supplied into the chamber 11 together with H2, and the conditions at this time are: temperature = 260-500°C pressure crab 0.5-1.5 Torr TERA carrier gas flow rate: 40S ( 1: CMTSA carrier gas flow rate: 2 SCCM112 flow rate: 10
0 SCCM, 1-2%wts at a growth rate of 1000 people/sin
Contains i^j! -Grow Si on the substrate 12;

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the drawings.

The present inventor conducted an experiment on film formation by the 1OCvD method, at a temperature of 260 to 500°C and a pressure of 0.5 to 1.5.
It was confirmed that setting within the range of Torr is optimal. If the temperature and pressure are less than the above range, AI
l film growth is significantly reduced, and temperatures above 500°C result in At
' is not preferable considering the melting point of 0.5 to 1.5
It was confirmed that Torr has almost no effect on film growth.

After setting the temperature and pressure as described above, referring to FIG.
3)+TSA (8l (R')3) and H2 were supplied as shown in the figure, and the gas was ejected from the gas supply section 16 toward the heated substrate 12 in a shower-like manner. The flow rates of these gases at this time are TIB8 (carrier gas 40 SCC gate) TSA (
When the carrier gas was set to 2 SCCM) H2 (100 SCCM), the AI growth rate was 1000 people/mi.
n, the actual amount of silicon in Al is 1 to 29 fiwt.
A contained thin film was grown on the substrate 12. Incidentally, the growth time and film thickness will be described later with reference to FIG.

An example of organoaluminum is tridisialium (TD
SA, Al (Sizes) 3) can also be used, and Figure 2 shows a line showing the relationship between the flow rate (the horizontal axis is taken in cc/win) and the silicon concentration (the vertical axis is the weight ratio, taken in wt%). It is a diagram. Line A is the carrier gas flow rate of TIBA 40cc/min. Line B is the carrier gas flow rate ff1.
30cc/min.

Line C shows the case where the carrier gas flow is 1t20cc/min. When the flow rate of the inorganic carrier gas is less than 1 cc/ll1in, -L of silicon
% is smaller than l, and if it is less than 1 cc/min, it will not solve the conventional problem, and if the flow rate of the carrier gas is made larger than 10 cc/l, the -t% of silicon will become too large, causing wire breakage. Although the risk of this is eliminated, the resistance value increases.

Figure 3 shows TIBA+H2 and TIB^+TSA+H
This is a diagram showing the relationship between the growth time (in minutes on the horizontal axis) and the film thickness (in μm on the vertical axis) in case 2. In the method of the present invention, the Al-5t alloy film grows to 1 in about 10 minutes. It is shown that the film grows to a thickness of .0 μm.

〔Effect of the invention〕

As described above, according to the present invention, by using a mixture of organic aluminum (TM8, TEA, TIBA, etc.) and inorganic aluminum (TSA, TDSA, etc.), the amount of silicon in A1.Si can be reduced. It has become possible to change the change with good controllability, and according to experiments, it has been confirmed that the adhesion of the step part due to vapor phase growth (c
There is also the advantage of improved coverage.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view of an embodiment of the present invention, Figure 2 is a diagram showing the relationship between the flow rate of source gas and the amount of silicon in the helium, and Figure 3 is the relationship between growth time and film thickness for 8E. FIG. - In Fig. 1, 11 is a chamber, 12 is a base plate, 13 is a susceptor, 14 is a heater, 15 is an exhaust pipe, and 16 is a gas supply section. Agent Patent Attorney Akifuku Agent Patent Attorney Yoshi Osuga
f&tji tana Figure 2 AI's Hejo Gin r4 Hi Gun 4's Seki 1 Shameful line flash Figure 3

Claims (2)

[Claims] (1) Heated substrate (12) in vacuum chamber (11)
) with a source gas containing organic aluminum (TIBA, TMA, TEA, etc.) and inorganic aluminum (TSA, TDSA, etc.) and hydrogen (H_2) gas to grow aluminum containing silicon on the substrate (12). A vapor phase growth method characterized by: (2) The degree of vacuum is 0.5 to 1.5 Torr, and the temperature is 2
The vapor phase growth method according to claim 1, wherein the temperature is 60 to 360°C, and the flow rates of organic aluminum and inorganic aluminum are each set in the range of 1 to 10 cc/min.