JPS60100661A - Vapor deposition method by sputtering - Google Patents

Abstract

PURPOSE:To form stably a thin compd. film having excellent film quality on a substrate in the stage of forming the thin film of various compd. by a vapor deposition method by ion beam sputtering on the substrate surface by irradiating simultaneously an ion beam contg. the reactive gas from an auxiliary ion source to the substrate surface. CONSTITUTION:A thin film of TiN is formed by a vapor deposition method by ion beam sputtering on the surface of the substrate 6 in a vacuum vessel 1. Ar is supplied as a sputtering gas to a main ion source 3 through a supply pipe 31 and a Ti target 5 is irradiated with a main ion beam 32 or electrically neutralized neutral particle beam 32. The Ti atoms of the target 5 evaporate by sputtering and are made incident in the form of sputtering particles 52 to the substrate 6. Gaseous N2 is supplied simultaneously to an auxiliary ion source 4 through a supply pipe 41 and is accelerated by ionization to irradiate the substrate 6 in the form of an auxiliary ion beam 42. The Ti atoms and N2 ions react on the substrate 6 thus forming the thin film of TiN.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a sputter deposition method used for forming various compound thin films.

Conventional Structure and Problems In recent years, spack evaporation has become popular as a method for forming various thin films. The spuck evaporation method is a method for forming a thin film on a substrate by irradiating high-speed ions onto the surface of a raw material solid called a target to perform sputter evaporation. In this case, the means for generating ions is 10-2To
A common method is to apply a high voltage between the targera 1- and positive (j) placed in a low vacuum of about rr to cause claw discharge.

On the other hand, a method in which a target placed in a high vacuum is irradiated with an ion beam generated from an independent ion source has recently attracted attention, and this method is called ion beam spackle deposition. In this case, the target and substrate are placed in a high vacuum, so there is less contamination by impurities.
Excellent patents can be obtained, such as that the crystallinity of the film is improved because the particles sputtered and evaporated reach the substrate without being scattered by gas molecules.

However, with this ion beam sputter deposition method, compounds,
In particular, various problems arise when forming a thin film of a compound of a metal element and a gaseous element. In other words, in such cases, the common method is to configure the target with a metal element, supply a gaseous element that reacts with the target into the atmosphere, and cause the reaction to occur on the substrate. In order to achieve this, it is necessary to apply a strong gas pressure, which would cause the above-mentioned features of the ion beam sputter deposition method to be lost and the film quality to deteriorate, and also cause the ion beam to scatter and cause sputter evaporation. Problems such as instability may occur. Note that even at low gas pressures, it is possible to cause a sufficient reaction by weakening the ion beam intensity and extremely reducing the sputter evaporation rate, but in this case, of course, the film formation rate will drop significantly.
Not practical.

Purpose of the Invention In view of such conventional problems, the present invention provides an ion beam
The object of the present invention is to provide a method for stably and rapidly forming a compound thin film having good film quality by sputter deposition.

Structure of the Invention The present invention provides an ion beam generated from a main ion source and a neutral particle beam that is electrically neutralized to a target made of a metal material to sputter and evaporate the metal material. By making the particles incident on the substrate surface and irradiating the substrate surface with an ion beam containing a reactive gas generated from a sub-ion source, a thin film consisting of a reaction product of a metal substance and a reactive gas is formed. This method of forming a compound allows a sufficient reaction to occur even under low gas pressure, thereby making it possible to form a compound thin film with good film quality at high speed.

The explanatory diagram of the embodiment is a schematic diagram showing an example of an ion beam sputter deposition apparatus used in carrying out the present invention. Here, titanium nitride (TiN
) will be described below. In FIG. 1, 1 is a vacuum container, 2 is a vacuum pump, 3 is a main ion source, 31 is a gas supply pipe to the main ion source, 4 is a sub ion source,
41 is a gas supply pipe to the sub-ion source, 5 is a target made of titanium, 6 is a substrate, and 61 is a substrate holder.

To form a thin film, first, vacuum container 1 is pumped with vacuum pump 2.
After evacuation to a high vacuum of, for example, 1.times.10 Torr or less, sputtering gas is introduced into the main ion source 3 through the introduction tube 31. For example, argon is used as the sputtering gas. The introduced gas molecules are ionized and accelerated in the main ion source 3, and then the main ion beam 3
2 and irradiates the target 5. Note that this main ion beam 32 may be electrically neutralized after leaving the main ion source 3 to become a neutral particle beam and irradiate the target, which will reduce the spread of the beam. In some cases, it is advantageous to have less. By irradiation with the main ion beam, the titanium atoms constituting the target 5 are sputter-evaporated and become a nupatter particle beam 62 which is incident on the substrate 6 . At the same time, nitrogen is introduced into the pipe 41 as a reactive gas.
After being introduced into the secondary ion source 4, ionized and accelerated, it is made incident on the substrate 6 as a secondary ion beam 42.

As a result, the titanium atoms that have reached the substrate react with nitrogen ions, and are deposited on the substrate as titanium nitride, forming a thin film. In this case, since nitrogen is supplied as accelerated ions, the reactivity is high, and the supplied nitrogen gas effectively contributes to the formation of a thin film. That is, even if the amount of gas supplied is small, a sufficient reaction occurs and a high quality titanium nitride film can be formed at high speed. In the case of this example, when the nitrogen supply amount was about 1 cc/=, a high-quality, completely nitrided film could be formed at a rate of about 1 μm/h over the entire surface of the substrate with a diameter of 5 mm. At this time, the increase in the pressure inside the vacuum container due to the inflow of nitrogen gas is 5 X 1 (T5T
orr, and no problems such as scattering of the ion beam occurred.

In contrast to the above results, in the conventional case (i.e., when no sub-ion source is used), assuming the nitrogen gas supply amount and other conditions are the same as above, the obtained film is extremely insufficiently nitrided), titanium, and titanium. The metal formation ratio (atomic ratio) of nitrogen and nitrogen is approximately 9=1
Met. Furthermore, even if the nitrogen supply amount is increased to 1 occ/=, the above component ratio in the film will only improve to about 6=4,
Nitriding was not complete. (1:1 if completely nitrided
becomes. ) When the nitrogen supply amount was further increased, the main ion beam was scattered due to the increase in the pressure inside the vacuum chamber, making it impossible to perform stable sputter evaporation. In addition, even if the nitrogen gas supply amount was 1ocr/=, if the intensity of the main ion beam was weakened and the amount of nupatta evaporation was significantly reduced, a nearly completely nitrided film was obtained, but in this case, the film formation The speed decreased significantly to approximately 0.2 μm/h.

As described above, according to the method of the present invention, compared to the conventional example,
A completely reacted, high-quality compound thin film can be obtained with a small amount of reactive gas supplied, and excellent effects such as a fast film formation rate and no unstable operation of the apparatus can be obtained.

Although the above embodiment describes the case of forming a titanium nitride thin film, the method of the present invention can be widely applied to other materials, including nitrides, oxides, and carbides of various metals and their alloys. etc. can be formed. In the case of carbides, methane (C
H3) or acetylene (02H2) may be used. In these cases as well, excellent effects similar to those of the above embodiments can be obtained.

Effects of the Invention As described above, the present invention is capable of stably forming a compound thin film with good film quality by irradiating the substrate surface with an ion beam of a reactive gas in the ion beam evaporation method. Moreover, it has the excellent effect of enabling formation at high speed.

[Brief explanation of the drawing]

The figure is a schematic diagram showing the structure of an ion beam sputter deposition apparatus used in an embodiment of the present invention. 1... Vacuum container, 2... Vacuum pump,
3... Main ion source, 31... Gas supply pipe to the main ion source, 4... Sub ion source, 41.
...Gas supply pipe to sub-ion source, 5...
Titanium target, 6...°'. Substrate, 61... Substrate holder, 32...
Main ion beam, 42...Sub-ion beam, 5
2...Spack particle beam.

Claims (1)

[Claims] An ion beam generated from a main ion source or a neutral particle beam obtained by electrically neutralizing the ion beam is irradiated onto a target made of a metal substance to sputter evaporate the metal substance, and the sputter evaporate particles of the metal substance is incident on the substrate surface, and an ion beam containing a reactive gas generated from a sub-ion source is irradiated onto the substrate surface to form a thin film made of a reaction product of the metal substance and the reactive gas. A sppack deposition method characterized by forming.