JPH10273776A - Titanium silicide target for sputtering - Google Patents

Abstract

(57) Abstract: Provided is a sputtering target for forming a titanium silicide thin film used as a diffusion prevention film of a semiconductor device. SOLUTION: The composition is characterized by having a composition of Si / Ti = 0.5 to 0.7 in molar ratio and having a density ratio of 95% or more.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to 4M and 16MD.
The present invention relates to a sputtering target for forming a titanium silicide thin film used as a diffusion prevention film of a semiconductor device such as an RM.

[0002]

2. Description of the Related Art It is generally known that a titanium silicide thin film is used for electrodes and wiring of a semiconductor device such as 4M or 16MDRM. The titanium silicide thin film for electrodes and wiring of this semiconductor element is TiSi _n (n: 2
To 2.5) (Si / Ti = 2 to 2.5),
The sputtering target for forming the titanium silicide thin film is also made of titanium silicide having the same composition as the titanium silicide thin film.

In order to manufacture a target made of titanium silicide, a titanium silicide powder as a raw material powder is first placed in a vacuum atmosphere of 1 × 10 ^-4 to 1 × 10 ^-3 Torr.
Pressure: 200 kg / cm ² , temperature: 1250-1400
After hot-pressing at 4 ° C. for 4 hours, the hot-pressed titanium silicide molded body is heat-treated, processed into a predetermined target shape, and finished.

[0004] The titanium silicide target thus obtained is plated with copper on the back surface, brazed on a pure copper cooling plate, set inside a sputtering apparatus, and sputtered to form a titanium silicide thin film. Form.

[0005]

In recent years, attempts have been made to use this titanium silicide thin film as a diffusion preventing film. However, conventional TiSi _n (n: 2 to 2)
2.5) Even if a titanium silicide thin film having a composition of (Si / Ti = 2 to 2.5) is used as a diffusion preventing film, a sufficient diffusion preventing effect cannot be obtained, and a titanium silicide thin film having a new composition is required. Had been.

[0006]

Means for Solving the Problems Accordingly, the present inventors have:
As a result of research on obtaining a titanium silicide thin film effective as a diffusion prevention film, (a) Si / Ti =
A titanium silicide thin film having a composition of 0.5 to 0.7 is effective as an anti-diffusion film of a semiconductor device, and a titanium silicide thin film having a composition of Si / Ti = 0.5 to 0.7 at this molar ratio is (B) obtained by sputtering a target having the same molar ratio of the composition.
When sputtering is performed using a target having a composition of Si / Ti = 0.5 to 0.7 at this molar ratio, generation of particles increases. To suppress generation of the particles, the density ratio of the target material is set to 95% or more. It was necessary to find out.

The present invention has been made based on this finding, and has a molar ratio of Si / Ti = 0.5 to 0.7.
And has a characteristic of a titanium silicide target for sputtering having a density ratio of 95% or more.

In the titanium silicide target for sputtering according to the present invention, the composition is expressed by a molar ratio of Si / Ti =
The reason why the density ratio is limited to 0.5 to 0.7 and the density ratio is set to 95% or more is that when the molar ratio of Si / Ti is out of the range of 0.5 to 0.7, it is sufficient as a diffusion preventing film for a semiconductor element. If the density ratio of the target is less than 95%, the generation of particles during sputtering is abnormally increased, which is not preferable.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The raw material powder has a maximum particle size of 10
A high-purity Ti powder having a purity of 0 μm: 99.99% was prepared. Further, after crushing a high-purity Si lump having a purity of 99.99999% with a ball mill, the maximum particle size is 50 μm with an air classifier.
To produce a high-purity Si powder. The high-purity Ti powder and the high-purity Si powder are blended into a V-type mixer, mixed, and then mixed with hydrogen and Ar (1 atm).
At 1200 ° C. for 1 hour to produce a titanium silicide powder having the component composition shown in Table 1. This titanium silicide powder was further pulverized with a ball mill to produce a titanium silicide powder having an average particle size of 10 μm or less.

On the other hand, a graphite mold having a cavity inner diameter of 350 mm is prepared, and the graphite silicide powder is filled in the graphite mold and 1 × 10 ^-4.
Hot pressing was performed in a Torr vacuum atmosphere at a temperature and time shown in Table 1 under the conditions of a pressure of 250 kg / cm ² . After measuring the density of the obtained hot-pressed sintered body, the hot-pressed sintered body was further machined to obtain a titanium silicide target of the present invention having a diameter of 300 mm and a thickness of 5 mm (hereinafter referred to as the present target).
1 to 9 and a comparative titanium silicide target (hereinafter, referred to as
1 (referred to as a comparative target).

Next, the targets 1 to 9 of the present invention and the comparative target 1 were placed on an oxygen-free copper cooling plate having a thickness of 10 mm.
After soldering using n-Sn eutectic solder, it was attached to a normal high-frequency magnetron sputtering apparatus, under the following conditions: substrate: Si wafer (152 mm), substrate temperature: 200 ° C., distance between substrate and target: 5 cm, Atmosphere: Ar atmosphere of 8 × 10 ⁻³ Torr, high-frequency output: 3 kw, film formation time: 2 minutes, and the diameter of the substrate by sputtering: 15
A titanium silicide thin film was formed on a 2 mm Si wafer, and the number of particles having a particle size of 0.3 μm or more formed on the Si wafer was counted by a commercially available particle counter. The results are shown in Table 1.

[0012]

[Table 1]

[0013]

As can be seen from the results shown in Table 1, Si / Ti = 0.5 to 0.7 and a density ratio of 9 for forming a titanium silicide thin film effective as a diffusion preventing film of a semiconductor device.
The targets 1 to 9 of the present invention having 5% or more generate less particles during sputtering, but have a density ratio of:
It can be seen that 94% of the comparative targets 1 generate extremely large particles.

As described above, the present invention can provide an excellent sputtering target for forming a titanium silicide thin film effective as a diffusion preventing film for a semiconductor device, and can greatly contribute to the development of the semiconductor industry. Things.

Claims (1)

[Claims] 1. A titanium silicide target for sputtering, which has a composition of Si / Ti = 0.5 to 0.7 in molar ratio and a density ratio of 95% or more.