JPS61190064A - Formation of thin titanium nitride film - Google Patents

Abstract

PURPOSE:To form a thin TiN film contg. TiN at a high ratio to a sample with lessened electric power consumption without increasing the temp. of the sample by making combination use of N ion irradiation and Ti vapor deposition and specifying the incident conditions and atmosphere conditions, etc. thereof. CONSTITUTION:The thin TiN film is formed on the sample 2 fixed to a supporting base 1 by irradiating an N ion beam 3 generated from an ion source 4 to the sample 2 and depositing by evaporation the Ti evaporated from an evaporating source 5 thereto in a gaseous N2 atmosphere in which a high vacuum is maintained. The region of <=1.0 N/Ti ratio of the incident number of N ions and incident number of Ti atoms per unit time to the sample 2, 5X10<-5>-2X10<-4>Torr gaseous N2 atmosphere pressure, 3X10<22>-3X10<23> pieces/ cm<2>/sec incident number of Ti atoms to the sample 2 and 10-30keV energy of N ions is used as the conditions for forming the above-mentioned thin film by controlling the pressure of the gaseous N2 to be introduced into the ion source 4, the N ion beam controlled by arc discharge and the evaporation rate of Ti controlled by the electron ray power of the evaporating source 5.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for forming a titanium nitride thin film on a sample by combining nitrogen ion irradiation and titanium vapor deposition.

[Conventional technology]

Methods for depositing titanium nitride on a substrate as a sample include the PVD method in which titanium is melted and evaporated and deposited in a nitrogen atmosphere of several mTorr to several Torr, and T t C.
There is a CVD method in which titanium-based gas such as 1z and nitrogen or a mixed gas of nitrogen-based gas are reacted at a high temperature of around 1000° C. and deposited on the substrate surface.

However, the PVD method has a problem in that the adhesion strength of the deposited film on the sample surface is poor, and the CVD method has a problem in that the physical properties of the sample (base material) change due to processing at high temperatures.

On the other hand, as a method to solve these problems, a method has been developed in which a titanium nitride thin film is formed on a sample using a combination of nitrogen ion irradiation and titanium vapor deposition.

To explain this with reference to FIG. 1, an ion beam (nitrogen ion beam) 3 from an ion source 4 is irradiated onto a sample 2 attached to a sample support stand 1 in a high vacuum atmosphere. , an evaporative material (titanium) 6 from an evaporation source 5 is deposited.

Thereby, a strong thin film can be formed while reducing the temperature rise of the sample 2.

[Problem that the invention seeks to solve]

In the method of combining nitrogen ion irradiation and titanium vapor deposition as described above, conventionally, as the number of nitrogen ions incident on the sample 2 per unit time increases, the proportion of titanium nitride TiN in the formed thin film increases. was known.

However, when increasing the number of nitrogen ions incident on the sample 2, the power consumption of the ion source 4 increases, and the power input to the sample 2 also increases, resulting in a large temperature rise in the sample 2. It arises.

Therefore, an object of the present invention is to provide a method for forming a titanium nitride thin film that can increase the proportion of titanium nitride TiN while solving such problems.

[Means for solving problems]

In the method for forming a titanium nitride thin film of the present invention, the ratio of the number of incident nitrogen ions to the number of incident titanium atoms per unit time to the sample, N/Ti, is N/
T i≦1.0, the atmospheric nitrogen gas pressure of the sample at that time is 5
X 10-5~2 X 10-'T o r r.

The number of titanium atoms incident on the sample is 3X10” to 3X1 per second.
0”/C1l+”, the energy of nitrogen ions is 1
The range from 0 to 30 KeV is used.

[Effect]

Under the above conditions, the ratio of the number of nitrogen ions incident on the sample to the number of titanium atoms incident per unit time is N
Even when /T i is 1 or less, titanium nitride is formed at a rate equal to or higher than that of the conventional method.

〔Example〕

In this embodiment as well, an apparatus having a configuration similar to that shown in FIG. 1 is used. In this case, for example, an electron beam heating type evaporation source is used for titanium evaporation, and an ion beam extracted from the ion source is used for nitrogen ions. The amount of titanium evaporated is determined by the electron beam power of the evaporation source, and the amount of nitrogen ion beam is determined by the nitrogen gas pressure introduced into the ion source and the power of arc discharge generated within the ion source. Further, nitrogen gas is supplied to the atmosphere of the sample.

The conditions for thin film formation are that the ratio N/Ti of the number of incident nitrogen ions to the number of incident titanium atoms per unit time to the sample is N/Ti51.0, and the atmospheric nitrogen gas pressure of the sample at that time is 5X], 0-5~2XIO-4Tor
r, the number of titanium atoms incident on the sample is 3 x 10” per second
~3 x 10''pieces/Cm'' and the energy of nitrogen ions is used in the range of 10 to 30 KeV.

Under the above conditions, the ratio of the number of incident nitrogen ions to the number of incident titanium atoms per unit time to the sample (ratio of the number of incident particles) is the ratio of titanium nitride and titanium oxide in the formed thin film to N/Ti. The results of measuring the ratio TEN/TiO by X-ray photoelectron spectroscopy (XPS) are shown in FIG. N/
The region where Ti>1 is based on the conventional method, and N/
The region where T i ≦1 is obtained by the method of the present invention.

Previously, it was only known that as the number of incident nitrogen ions increased, the proportion of titanium nitride TiN in the formed thin film increased, but as a result of various experiments this time, under the above conditions, the number of incident particles increases. Even if the ratio N/Ti is 1 or less, the target titanium nitride TiN is equivalent to or higher than conventional
was found to be formed.

In this case, the ratio N/Ti of the number of incident particles is N/Ti
51. o condition allows the required number of nitrogen ions to be reduced, thereby reducing the power consumption of the device, and in particular the ion source.

In addition, since the power applied to the sample during thin film formation can also be reduced accordingly, it is also possible to suppress the temperature rise of the sample and suppress changes in its physical properties. Moreover, this reduces restrictions from the sample, so the range of application of this thin film forming method can be greatly expanded, and for example, it becomes possible to form thin films on plastics, silicone rubber, polymer films, and the like.

Furthermore, the thickness of the thin film formed is determined by titanium, so if you want to increase the film thickness, it is necessary to increase the amount of titanium.
As can be seen from Figure 2, in this invention, unlike the conventional method, by increasing the amount of titanium, the ratio of the number of incident particles N/T
Since i decreases and the target titanium nitride TiN increases, titanium nitride with a predetermined thickness can be quickly formed, thereby improving productivity.

〔Effect of the invention〕

As described above, in the present invention, it is possible to increase the proportion of titanium nitride TiN in the formed thin film to a greater extent than the conventional one, reduce the power consumption of the apparatus, and suppress the temperature rise of the sample. You can also do it. Furthermore, productivity of thin films can also be improved.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing an apparatus used in a method for forming a titanium nitride thin film using both nitrogen ion irradiation and titanium vapor deposition. FIG. 2 is a diagram showing the measurement results of the ratio of titanium nitride and titanium oxide in the formed thin film, Ti N /T i O, with respect to the ratio N / Ti of the number of incident nitrogen ions and titanium atoms during thin film formation.

Claims (1)

[Claims] (1) In the method of forming a titanium nitride thin film on a sample using a combination of nitrogen ion irradiation and titanium vapor deposition, the conditions for thin film formation include the number of incident nitrogen ions and the number of incident titanium atoms per unit time on the sample. The ratio N/Ti is N/T
i≦1.0, the atmospheric nitrogen gas pressure of the sample at that time is 5×1
0^-^5~2x10^-^4 Torr, the number of titanium atoms incident on the sample per second is 3x10^2^2~3x10^2
^3 pieces/cm^2, the energy of nitrogen ions is 10-3
A method for forming a titanium nitride thin film, characterized in that a region of 0 KeV is used.