JPS62153109A - Production of titanium silicide - Google Patents

Abstract

PURPOSE:To produce high-purity titanium silicide of an arbitrary shape, by mixing titanium with silicon or titanium silicide and melting and reacting the mixture with electron beam. CONSTITUTION:Titanium is mixed with silicon or titanium silicide. The mixture is made to react by melting with electron beam in high vacuum of about <=10<-6>Torr. Impurity components are removed simultaneous to the above reaction to obtain a purified product. For example, the above mixture 2 is charged into a water-cooled copper hearth 1, evacuated and melted with electron beam 3. The obtained titanium silicide is turned upside down and the electron beam melting is repeated. A high-purity titanium silicide having arbitrary composition can be produced by this process.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention is a method for producing highly pure titanium silicide.

Titanium silicide is one of the most promising materials for electrode and wiring materials for VLSI. Titanium silicide has been actively researched because its electrical resistance is extremely low and conventional techniques can be used, but due to its extremely poor purity, its excellent properties cannot be fully utilized. At present, there is a need for a method for producing high-purity titanium silicide.

[Conventional technology] Conventionally, titanium silicide has been produced by target, vapor deposition, or CVD.
(Chemical vapor dip
on). However, the target material and vapor deposition material are made of titanium and silicon powder,
(cold isostatic pressing) and HIPt hot isostatic pressing), and since it is made from powder, it contains an extremely large amount of impurities such as oxygen.In addition, in CVD, purity Although relatively good products can be obtained, there are problems with the equipment because corrosive gas is used, and it is not suitable for mass production.

[Problem that the invention seeks to solve]

The presence of impurities in titanium silicide increases the resistance value and causes malfunction, so it is necessary to reduce the impurities as much as possible. However, in the above manufacturing method, even if the product is relatively pure, gas components such as oxygen and IFe,
Magnetic impurities such as Oo and Ni, as well as alkali metals,
It contains alkaline earth metals and the like as shown in Table 1. This is because powder is used as a raw material, which causes an increase in gas components such as oxygen, and also because of the mixing of metal impurities during the pulverization of the raw material.

Table 1 The present invention involves melting and reacting a mixture of titanium and silicone or titanium silicide with an electron beam in a clean atmosphere of high vacuum, simultaneously removing and purifying impurities, and solidifying it in a water-cooled crucible of any shape. The present invention provides a method for producing titanium silicide, which allows highly pure titanium silicide to be obtained in any shape.

[Means for solving problems]

The gist of the present invention is a method of producing highly pure titanium silicide by reacting a mixture of titanium and silicon or titanium silicide by electron beam melting.

The details will be explained below.

[For production]

The titanium and silicon used in the present invention may have any shape without any particular problem, but it is preferable that the specific surface area is as small as possible and the purity is high. Alternatively, a mixture of titanium and silicon may be used.

This raw material is subjected to electron beam melting in a high vacuum of 10'torr or higher to react and purify it at the same time. When melting in a water-cooled copper hearth, the shape of the hearth is set to an arbitrary shape, and melting is performed several times. Alternatively, it may be transferred into another mold and formed into an arbitrary shape. Furthermore, the method is not limited, and may be a method of continuously feeding titanium and silicon or a mixture of titanium and silicon, melting with an electron beam, drip melting, and pulling out an ingot.

By changing the composition of raw material titanium and silicon, the composition of the produced silicide can also be changed arbitrarily.

Next, the present invention will be explained based on the drawings, but the present invention is not limited to these devices in any way as examples are only shown.

Figure 1 shows that titanium and silicon or a mixture of titanium and silicon of any composition is fed into a water-cooled copper hearth.
After exhausting the gas to a pressure higher than F'torr and sufficiently exhausting, it is melted by the electron beam shown in (2). Furthermore, the melted titanium silicide (■) is turned over and melted with an electron beam again. This operation is repeated several times to ensure sufficient reaction and purification.

Figure 2 shows that a titanium rod and a silicon rod or a mixture of titanium and silicon are continuously supplied, followed by melting reaction with an electron beam ■, solidified on a pace metal for purification, and then drawn. This is a device that continuously produces titanium silicide ingots.

〔Effect of the invention〕

By using the above apparatus, titanium silicide with improved purity and no external contamination can be produced in an arbitrary shape. Although the invention will be described, the invention is not limited in any way by these Examples.

Example 1 Using the apparatus shown in Figure 1, the quality and yield of titanium silicide obtained by performing electron beam melting three times for 5 minutes using the raw material titanium and silicon having the quality shown in Table 2 was as follows. The rates are shown in Table 2.

fi+ in the table is raw material titanium 138519. Raw material silicon 4
, 02419 is dissolved, and (2) is the case where a mixture of raw material titanium and silicon 7.41009 is dissolved. In both cases, very high purity titanium silicide was obtained in good yield.

Example 2 Using the apparatus shown in Fig. 2, titanium, do, and silicon rods were continuously fed and melted into a hydribule with a cross-sectional area ratio of approximately 1:2.21. Table 2 shows the quality of an ingot produced.
This is shown in (3). In this case as well, highly pure titanium silicide was obtained in good yield.

BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1 and 2 show an example of an apparatus for carrying out the present invention. ■・・・Water-cooled copper hearth ■・・・Electron beam■,■
...Raw materials, titanium silicide patent applicant Toyo Soda Kogyo Co., Ltd. Engraving of drawings (no changes to the content) Figure 1 Figure 2 Procedures formal manuscript (method) % formula % 1 Indication of case 1985 patent application no. No. 292436 2. Name of the invention 3. Process for producing titanium silicide 3. Relationship with the amended case Patent applicant address 4560 Oaza Tomita, Shinnanyo City, Yamaguchi Prefecture 746 Toyo Soda Kogyo Co., Ltd. Patent Information Department Telephone number (505) 4471 As per the engravings and attachments of the specification and drawings originally attached to the application (no changes to the contents).”

Claims (1)

[Claims] A method for producing titanium silicide, which is characterized by simultaneously molding a mixture of titanium and silicon or titanium silicide by reacting them by electron beam melting.