JPH02149663A - Formation method of titanium nitride film by dynamic mixing - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to surface modification technology for metals and non-metals, and in particular, to modify the surface of a sample by simultaneously irradiating a nitrogen ion beam and vapor deposition of titanium metal. The present invention relates to a method of forming a titanium nitride film.

[Conventional technology]

In order to improve the corrosion resistance and abrasion resistance of structural members, there are various methods of forming a film on the surface of a sample.
Samples can be prepared using the PVD method, which forms a titanium nitride film by dissolving and evaporating titanium in a nitrogen atmosphere of from r to several Torr, or by reacting a mixed gas of titanium-based gas and nitrogen-based gas at a high temperature of around 1000'C. CV to form titanium nitride film on the surface
There are methods such as D method. However, these have advantages and disadvantages,
In the PVD method, the adhesion strength of the film is poor, and in the CVD method, the adhesion to the substrate is good because it is processed at high temperatures, but deformation of the substrate becomes a problem, and furthermore, various physical properties such as coarsening of crystal grains occur. The problem is that it involves change.

On the other hand, as a method to solve these problems, a film formation method using the so-called Daidemic mixing method has been proposed, in which a titanium nitride film is formed on the sample surface by simultaneously irradiating nitrogen ions and titanium vapor deposition. For example, JP-A-61
JP-A-190064 proposes a method for forming a titanium nitride film using this method. However, according to this method, the number of incident titanium evaporated atoms per second is 3XIQ22~3
It is stated that 23 XIQ/ad are required. Here, the number of titanium evaporated atoms per unit time, Ti, is determined by the evaporation rate being R (cm/sec) and the density of titanium being p (
g/ad).

When 1 mole of titanium is M (g/moQ), it is expressed as n: Avogadro's number 6 x 1023/+no Q.

For titanium, ρ=4.51 g/moQ, M=47
．． By substituting 9 g/moQ, the titanium deposition rate becomes R=0.53 to 5.3 .mu./sec from equation (1). Furthermore, while N/Ti≦1.0, by the way, N =
When trying to form a film at a ratio of T i, that is, N/Ti=1.0, the number of incident N is as follows.

The number of incidences of N per unit time is N=□...(2) e:
Constant load of electrons 1. ．． 6X10-1f' Coulomb D: Ion beam current density Therefore, D is (1) and (2) from equations D=4.8
X103 to 4.8 X104 A/cJ. That is, it is stated that the condition that N/T i ≦1.0 can reduce the required number of nitrogen ions, thereby reducing the power consumption of the device, specifically the ion source. However, the deposition rate of Tj and the current for accelerating the ion beam are both enormous values, and these points have not been taken into consideration. Furthermore, films formed by changing the ratio of Tj and N come to have various crystals, but these points have not been taken into account in the prior art.

[Problem to be solved by the invention]

The conventional method described above does not take into account the titanium deposition rate and the value of the ion beam acceleration current per unit time when forming the titanium nitride film, which poses a problem in forming the titanium nitride film. .

For example, in the case of an evaporation source 1, in the electron beam heating type evaporation source that is usually used, the evaporation rate is from several people/sec to several tens of people/s.
ec, and the deposition rate by the method described above is 0.53~
In order to obtain 5.3■/sec, it becomes an evaporation source with a huge power supply capacity, and the evaporation rate must be 0.53(1)/sec to 5.3■
/sec cannot form a thin film. Regarding the ion source, in the case of thin film formation by dynamic mixing, the acceleration current of the ion beam is 0.1 to several thousand mA/, taking into account the titanium deposition rate and the ratio of Ti to N.
csj is 8 degrees.

This is similar to the case of the evaporation source described above.

Furthermore, when titanium nitride films are formed by changing the ratio of Ti and N, films with various crystals are formed by changing the ratio of Ti/H, but this point was not taken into consideration either. .

An object of the present invention is to provide a method for forming a titanium nitride thin film that has a golden color by controlling the ratio of Ti and N and making it possible to control the crystals of the film to be formed.

[Means to solve the problem]

The above objective is to set the number N of nitrogen ions incident on the sample per unit time as a condition for film formation to N=lX10" ~ I
The irradiation angle of the ion beam is 45° in the range of
/N≧0.5, and after forming an arbitrary film, this is achieved by implanting only an ion beam.

[Effect]

In the present invention, the number N of nitrogen ions incident per unit time is I x 10" to I x I Ql" pieces/cm2-s.
Since it is in the ec range, the ion beam can be easily accelerated.

In addition, even for titanium evaporation sources, the evaporation rate is several people/se.
c~several tens of people/sec, the film can be easily formed using an ordinary electron beam heating type evaporation source.

〔Example〕

Embodiments of the present invention will be described below with reference to FIG.

An ion beam 2 extracted from an ion source 1 is used for nitrogen ions. The amount of nitrogen ion beam is defined by the amount of nitrogen gas introduced into the ion source 1 from the gas controller 3 and the power of the arc discharge generated within the ion source. An electron beam heating evaporator 4 is used for titanium deposition.

The amount of evaporation of titanium 6 is determined by the electron beam power adjusted in control table @5. In addition, 7 is a sample, 8 is a vacuum container,
9 is a vacuum pump, 10 is a cooling water, 11 is an ion beam power source, and 12 is a shutter.

The conditions for film formation are that the number N of nitrogen ions incident per unit time is N=IX10'' to lX1016/d・Sec,
The nitrogen atmosphere gas pressure at that time is lXl0-'~2X1
0-'Torr, and the ratio T of the number N of nitrogen ions incident and the number Ti of titanium atoms incident per unit time to the sample.
Film formation is performed with i/N being 0.5≦T i/N.

The inventors formed various titanium nitride films under the conditions described above and discovered the following.

FIG. 2 shows the crystalline region of a titanium nitride film formed on the surface of stainless steel by the dynamic mixing method under the conditions described above. The horizontal axis in the figure is the titanium deposition rate R (person/5ee) per unit time. That is, it represents the number Ti of incident titanium atoms per unit time. Here, the relationship between R and Ti is as shown in equation (1).

On the other hand, the vertical axis is the nitrogen ion current density D (mA, cJ). That is, it represents the number N of nitrogen ions incident per unit time. Here, the relationship between N and D seems to be shown by equation (2). By the way, when the ratio of T i /H is Ti=N, the relationship between R and D is e'n' ρ from equations (1) and (2).

Incidentally, R at D=1mA/a1 is R#11 people/s
It becomes ec. Here, the ratio of T i /N is replaced with the ratio of R/D, and the ratio is expressed as K as follows.

11 D According to the findings obtained from the inventors' experiments, the value of K is ≦0.
．． In No. 5, sputtering is performed and no pores are formed. K
When the value of is gradually increased to K2O,5, a film starts to be formed, and a titanium nitride crystal film is obtained. and,
As the value of K increases, the crystalline film becomes TiN, then TiN
and TizN mixed film, then TiN, Ti2N and T
A mixed film of i and a crystal film of only Ti can be obtained, but a crystal of TiN can no longer be obtained.

On the other hand, the crystal structure of a film is the most fundamental physical property, especially
Structural thin films have abrasion resistance, corrosion resistance, and hardness, while functional thin films have such properties as magnetic permeability, density, and transmittance. Therefore, the inventors paid attention to the above-mentioned experimental results, and made it possible to make various mixed films such as TizN and Ti in addition to a crystalline film made only of TiN, depending on the purpose. This method is applicable not only to the formation of titanium nitride thin films, but also to other thin films such as aluminum nitride and silicon nitride.

The inventors also found that after forming the film as described above,
Stop the titanium deposition and change the irradiation angle of the nitrogen ion beam to 4
It has been found that by irradiating the film at an angle of 5° for several minutes to several tens of minutes, the color of the film becomes golden.

〔Effect of the invention〕

According to the present invention, by controlling the Ti/N ratio and forming the film, it is possible to form a mixed film of titanium nitride with various crystals, and it has excellent wear resistance, corrosion resistance, and high hardness. Structural thin films can be easily formed.

[Brief explanation of the drawing]

FIG. 1 is a system diagram of a thin film forming apparatus for forming a titanium nitride film according to an embodiment of the present invention, and FIG. 2 is an explanatory diagram of experimental results showing crystalline regions of the formed film.

Claims (1)

[Claims] 1. In a method of forming a titanium nitride film on a sample surface by simultaneously performing vapor deposition of a nitrogen ion beam and titanium metal, the number N of the nitrogen ions incident per unit time is N=1×
10^1^5 ~ 1 x 10^1^6 pieces/cm^2・sec
irradiation in the range of A method for forming a titanium nitride film using dynamic mixing, which is characterized in that after forming a thick film, the evaporation is stopped and the film is formed by irradiating only a nitrogen ion beam.