JPS62150822A - Manufacture of thin film - Google Patents

Abstract

PURPOSE:To form a thin film having no defect by independently applying a DC voltage to two high melting point metal silicide targets having different composition ratios to obtain a thin high melting point silicide film having arbitrary composition. CONSTITUTION:Ar gas is introduced into a vacuum vessel 1, a negative DC voltage is applied from a variable power source 4 to a WSi target 6 and a WSiz target 7 to execute sputtering. At this time, supplied power is regulated to deposit a thin WSix film having object composition ratio on a wafer 5 which laterally moves. Since the Si or W film is not solely bonded to any position of the inner wall of the vessel 1, the bonded film is not separated fro a long period to obtain the WSix film having no defect.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method of sputter-depositing a high-quality refractory metal silicide thin film by arbitrarily adjusting the composition ratio in, for example, the manufacturing process of semiconductor integrated circuits. be.

[Conventional technology]

Conventionally, as a method of this type, there is a co-sputter method shown in FIG. In Fig. 2, ■ is a vacuum container, 2 is an St target, 3 is a target of a high melting point metal such as Ti, Mo, Ta, W, etc., 4 is a variable power supply that is independently and regulatedly applied to each target, and 5 is a Moving left and right facing target 2.3, high melting point metal silicide (T i S IX+
MoSix) is a substrate on which a thin film is deposited.

Next, the operation will be explained. IO-”T inside the vacuum container 1
For example, in an Ar gas atmosphere of approximately o r
Perform sputtering using ions. Atoms ejected from the target are deposited on the surface of the substrate 5 moving oppositely in front of it, forming a thin film. At this time, if the power supplied to the target is adjusted, the Si contained in the deposited film and the high melting point The ratio of metals can be controlled.

[Problem that the invention seeks to solve]

Since the conventional co-sputtering apparatus is configured as described above, Si is deposited on the inner wall surface of the vacuum chamber 1 facing the target.
and refractory metal are deposited separately.

Usually, the vacuum container 1 is made of stainless steel, but since both Si and high-melting point metals have poor adhesion, peeling occurs frequently and there is a high probability that flakes will adhere to the surface of the substrate 5 during film formation. This can cause various defects. In addition, high purity S
Since i is insulative, there is a problem in that direct current sputtering, which is easy to control power and has little risk of damaging the substrate, cannot be performed.

The present invention has been made in view of these points, and its purpose is to prevent flakes from adhering to the inner wall of a vacuum container such as stainless steel, which is caused by the peeling off of Si and high melting point metals. The objective is to stably obtain a high melting point metal silicide thin film.

[Means for solving problems]

In order to achieve such an object, the present invention uses two high melting point metal silicide targets 7) with different composition ratios and uses a simultaneous sputtering method in which the applied power is independently varied to produce high melting point silicide of any composition. This method is used to obtain a thin film.

[Function] The high melting point metal silicide produced by applying the present invention has the following properties:
Adhesive force to stainless steel etc. is stronger than that of Si or high melting point metals, and peeling is less likely to occur. Furthermore, since it is electrically conductive, direct current sputtering is possible, and composition control can be performed easily, accurately, and stably.

〔Example〕

The formation of a tungsten silicide (WS iX) thin film for electrodes in the manufacturing process of a semiconductor integrated circuit will be described below as an example of the thin film manufacturing method according to the present invention, with reference to FIG. In FIG. 1, 1 is a vacuum vessel, 6 is WSi, target, and 7 is W
Si, target, 4 is a DC power variable power supply that independently applies DC voltage to target 6.7, 5 is target 2.
W5i moving left and right opposite to 3, St depositing a film,
This is a semiconductor wafer made of GaAs or the like as a substrate. WSt
, Target 6, W Si*Target 7 may be a compound made by mixing and sintering W and St powders,
Alternatively, a mosaic target in which W and Si are arranged in a mosaic pattern may be used. y and 2 can be selected in the range of about 0.2 to 4.

Next, the operation will be explained. IQ-”T in vacuum container 1
Ar gas of about orr is introduced, and a negative DC voltage is applied to the target 6.7 to perform sputtering. At this time, the supplied power is adjusted and WSiX with the desired composition ratio is placed on the wafer 5.
Deposit a thin film. - Examples include WSio, 2 and WSio,
When compound target No. 3 is used, the composition of the deposited film is changed by adjusting the power to W S j o, is ~ W
It could be set arbitrarily within the range of S+, . It is obvious that the desired composition range can be changed by selecting the target composition according to the desired composition. Since the Si or W film does not adhere to any part of the inner wall of the vacuum vessel 1, peeling of the adhered film does not occur over a long period of time, resulting in a defect-free WS.
An iX film could be obtained.

Furthermore, since the sputtering in this example is direct current sputtering, it has been confirmed that the substrate 5 is less likely to be damaged by high-energy particles by obtaining good characteristics in the Schottky bonding with the GaA1 plate.

Furthermore, since DC sputtering is used, there is no need to consider changes in impedance due to differences in target materials.
No adjustment circuit such as a high frequency matching circuit is required at all, making work easier.

In the above embodiments, WSi is used as the film forming material, but any material that is difficult to adhere to stainless steel when used alone can be used as long as it has a strong adhesion force when mixed. As high melting point metal silicide, in addition to WSi, TiS
There are f*+ MoS iX, TaS L, etc.

Furthermore, it is also possible to combine different refractory metal silicide targets, for example T i g
W y S 1 m, Ti, Mo, Si, etc. can also be formed.

〔Effect of the invention〕

As explained above, the present invention uses two high melting point metal silicide targets with different composition ratios and obtains a high melting point silicide thin film of any composition by a simultaneous sputtering method in which the applied power is independently varied. Because the film-forming material can be made to have strong adhesion, film-forming has the effect of forming a defect-free thin film without flakes occurring from the inner wall of the vacuum chamber, and since direct current sputtering can be performed, it is possible to form a thin film with no defects. This has the effect that damage is less likely to occur and control can be made easier and more stable.

[Brief explanation of drawings]

FIG. 1 is a block diagram for explaining an embodiment of the thin film manufacturing method according to the present invention, and FIG. 2 is a block diagram for explaining a conventional thin film manufacturing method. l...Vacuum container, 4...Variable power supply, 5...
・ ・Substrate, 6 ・ ・ ・WSi, Target, 7
・ ・ ・WSi, target.

Claims (1)

[Claims] A method for producing a thin film, characterized in that a high melting point silicide thin film of any composition is obtained by a simultaneous sputtering method in which two high melting point metal silicide targets with different composition ratios are used and the applied power is independently varied.