JPH0448745A - Evaluation of wear resistance of thin film - Google Patents

Abstract

PURPOSE:To accurately evaluate the wear resistance of a thin film by injecting suspension obtained by suspending fine particles of a high hardness material in water to the surface of the film, and detecting a fine wear generated on the surface of the film. CONSTITUTION:As a thin film 1, for example, a titanium nitride film (0.2mum in thickness) formed by an ion plating method on an Si wafer is used, and suspension 4 obtained by suspending aluminum oxide (15mum in mean particle size) as injecting fine particles together with surfactant in water is injected from an injecting nozzle 2 having 7kg/cm<2> of injecting pressure and 0.2mm of nozzle diameter. The depth of a wear is calculated from the deviation of an interference foire by a repetitive reflection interference method. Wear is advanced at a constant speed to the depth near the thickness of the nitride film (0.2mum). Even if the surface at this time is observed by an optical microscope (magnification, 400), no peeling of the nitride film is seen.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to an evaluation method for evaluating the wear resistance of a thin film.

[Conventional technology]

In recent years, fiI films (with a thickness of several microns or less) of various materials have been formed by vacuum evaporation, sputtering, CVD, etc., and have come to be used for various purposes. among them,
In particular, attention has been focused on improving wear resistance by using thin films of highly hard materials. As a means of evaluating the wear resistance of these thin films, [Solid Lubrication Handbook J p
, 371-326 (Zai Shobo, 1982), a pin-on-disk type abrasion test suitable for evaluating bulk materials, and a scratch test using a diamond indenter, etc. have been conventionally used.
ansactIonsVol, 31. p, 228 (19
A method of performing polishing (Borissini) using fine particles as shown in 8g) and evaluating it based on the polishing rate has also been considered.

FIG. 3 is a schematic diagram for explaining a pin-on-disk type wear test, in which a pin 11 as a sample is pressed against a disk 12, and the disk 12 is rotated for a certain period of time to examine the degree of wear.

In addition, Figures 4(a) and (b) show a test machine of the type that performs polishing using fine particles, and a suspension of fine particles dissolved in water together with a surfactant, etc., is used as shown in Figure 4(a). It is dripped onto the polishing pad 22 from the dripping nozzle 23. The sample 21 fixed to the sample holder 24 shown in FIG. 4(b) is pressed onto the polishing pad 22, and the polishing pad 22 and sample 21
Polishing is performed while moving relatively, and the polishing speed (
Wear resistance is evaluated based on the polishing depth (polishing depth per unit time). Note that 25 is a rotation axis of the sample holder 24.

[Problem to be solved by the invention]

However, with the above-mentioned pin-on-disc or scratch-based wear resistance evaluation methods, it is difficult to adjust the minute pressure, and the polishing method causes so-called surface wobbling due to stress concentration at the sample edge. This makes it impossible to accurately evaluate the amount of wear. Also, in the blasting method, the thin film will not wear unless the kinetic energy is increased when sand particles are injected, and if the kinetic energy is increased, the force will not only be applied to the surface of the thin film, but will also be applied to the underlying layer. There were problems in that it caused peeling of the thin film and macroscopic deformation.

This invention was made to solve the above-mentioned problems, and aims to provide a method that can accurately evaluate the wear resistance of a thin film without peeling or macroscopic deformation of the thin film. It is something.

[Means to solve the problem]

A method for evaluating wear resistance of a thin film according to the present invention involves spraying a suspension of fine particles of a highly hard material in water from a spray nozzle onto the surface of a thin film formed on a substrate, and evaluating the degree of wear of the thin film. It is something to detect.

[Effect]

In this invention, the wear resistance of the four films can be accurately evaluated by spraying a suspension of fine particles of a highly hard material in water onto the surface of the thin film and detecting the minute abrasion that occurs on the outermost surface of the thin film. .

〔Example〕

This invention will be explained below.

FIG. 1 is a schematic diagram of an apparatus for evaluating the wear resistance of thin films based on the present invention. In this figure, 1 is a thin film as a sample formed on a substrate (wafer) by various methods, 2 is an injection nozzle, 3 is a pressurized tank, and 4 is a suspension contained in this pressurized tank 3. , this suspension #14 is a suspension of fine particles of a highly hard material in water together with a surfactant. In this way, when a surfactant is used, fine particles can be stably dispersed in a solution.

For example, the bulk hardness of fine particles of a high hardness material is as follows.

Aluminum oxide Hv 1800 Silicon carbide H・25°0 Also, the particle size is approximately 0.3 μm to 0.5 m
Approximately m is applicable.

As the thin film 1, for example, a titanium nitride film (thickness 0.2μ+n) formed on the S1 sea urchin by an ion-blating method.
Using a suspension 4 in which aluminum oxide (average particle size 15 μff+) was suspended in water together with a surfactant as fine particles for injection, the injection pressure was 7 kg/cffl, and the nozzle diameter was 0.2 en.
It was injected from the ffI injection nozzle 2.

The wear depth was calculated from the deviation of interference stripes using repeated reflection interferometry. Figure 2 shows a plot of maximum wear depth versus injection time. Film thickness of titanium nitride film (0,2
Wear progresses at a constant speed up to a depth near μff+). In addition, the surface at the time of O was examined using an optical microscope (magnification: 40
Even when observed at 0x magnification, no peeling of the titanium nitride film was observed.

The same titanium nitride film was evaluated using the conventional scratching method and polishing method, but the scratching method used a diamond needle (
The tip curvature radius is approximately 10101I, the load is 3g, and the relative speed is 10.
Scratched at cm/min.

As a result, the titanium nitride film did not wear out, only scratches and raised areas were formed around the scratches due to plastic deformation. On the other hand, in the polishing method, polishing was performed with an aluminum oxide abrasive with an average particle size of 1 μm at a surface pressure of 0.3 kg/c+n'', but only the edges of the sample (near the outer periphery of the Si raw material) were ground, but the center of the sample was not worn. Ta.

In addition, as another example, a protective film (a carbon film formed by sputtering, thickness 0.05 μm) of a metal thin film type magnetic disk medium was evaluated using the method according to the present invention. The fine particles for injection at this time are silicon carbide (average particle size 5,17+1
1), injection pressure 5kg/cffI', 7th diameter 0.1r
Injected at nm. In the case of a carbon film formed at a sputtering gas pressure of 2InTO, no peeling occurred and the carbon film thickness (0.05
It took about 10 minutes to remove .mu.m). On the other hand, the sputtering conditions for the carbon film were different from those in the above example, and the gas pressure was 30 r.
When a wear test was conducted under the same conditions for a carbon film formed at n Torr, it took about 18 minutes to remove O,OS μm. As described above, in the method according to the present invention, it was possible to clearly correlate the slow sputtering conditions with the difference in wear resistance of the carbon film.

In the above example, aluminum oxide and silicon carbide were used as the injection particles, and the injection pressure was 7 kg/cffI2 and 5k.
g/cm”, and the nozzle diameter is 0.2 m + n and 0.1 r.
An example of n rn is shown, but the fine particles are not limited to chromium oxide, silicon nitride, and diamond.

Iron oxide etc. can also be used, and the injection pressure is 1.5kg/Cm.
The pressure may be set appropriately within the range of 20 kg/cm2 to 20 kg/cm2.Also, although the embodiment shown in Fig. 1 shows an example using the pressurized tank 3, a high-pressure pump may also be used.Also, the nozzle diameter The same effect can be achieved if the thickness is in the range of 0.05 mm to 0.5 mm.Furthermore, the thin film to be evaluated for wear resistance may be any ceramic thin film, metal thin film, organic polymer thin film, etc. Needless to say, the film thickness may be 0.5ffIIr+ or less.

〔Effect of the invention〕

As explained above, the present invention detects the degree of wear of fipFIA by injecting a suspension of fine particles of a highly hard material in water from an injection nozzle onto the surface of a thin film formed on a substrate. Therefore, there is no peeling of the thin film during the evaluation test, and the wear resistance of the thin film can be accurately evaluated.

[Brief explanation of drawings]

Fig. 1 is a schematic diagram of an apparatus for explaining an embodiment of the wear resistance evaluation method of the present invention, and Fig. 2 shows the relationship between the wear resistance depth of the titanium nitride film and the injection time in the embodiment of the invention. 3 and 4 are perspective views showing conventional examples. In the figure, 1 is a thin film, 2 is an injection nozzle, 3 is a pressurized tank, and 4 is a suspension. Agent Masuo Oiwa (2 others) Figure 1 Figure 2 Convex Figure 3 Injection time (minutes)

Claims (1)

[Claims] Abrasion resistance of a thin film, characterized in that a suspension of fine particles of a highly hard material suspended in water is injected from a spray nozzle onto the surface of a thin film formed on a substrate, and the degree of wear of the thin film is detected. Gender evaluation method.