JPS62191471A - Manufacture of target for sputtering device - 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 Field of Industrial Application The present invention relates to a method for manufacturing a target for a sputtering device, and particularly to a method for manufacturing a target for a sputtering device, and in particular, a high-density molybdenum silicide suitable for forming a gate electrode material used in MoS-rc. The present invention relates to a method of manufacturing a target for a sputtering device comprising:

2. Description of the Related Art In recent years, silicides of high melting point metals such as molybdenum and tungsten, which have low specific resistance, have been used for gate electrodes of MoS type LSIs. A sputtering method using a target made of silicide of a high melting point metal is mainly used to form a replica of such a high melting point metal silicide.

Targets made of high-melting point metal silicide, especially molybdenum silicide, are generally made from a mixed powder of molybdenum powder and silicon powder, or by the Hola 1-press method or pressureless vacuum sintering method using molybdenum silicide powder as the raw material. Manufactured in

[Problems to be Solved by the Invention] When producing a target with a relative density of 90% or more by the press method, the heating temperature is 1400°C or more and the pressure is 1.
00 ko/am' or more is required. However, when a carbon material is used for the pressurized container, there is a problem of carbon (C) being mixed into the target material due to the high heating temperature, and when a ceramic material is used for the pressurized container, the target material (Although there was no contamination with material A, damage to the container was a problem.

For example, when molding a single target with a diameter of less than 180 mm and a thickness of less than 10 mm, it can be consolidated uniformly to the center of the diameter at 90% or more, but a diameter of 220 mm for mass production is possible.
When hot press molding a target with a thickness of 40 mm, a density of 90% or more can be obtained at the outer periphery, but a density of 8 at the center.
0%, resulting in insufficient compaction and uneven compaction of Targetera 1 to itself, and there were also problems in that particulates adhered to the sputtered film and impaired film properties.

On the other hand, when using the pressureless vacuum sintering method, the sintering temperature is 170
At 0°C, only about 60 to 70% of the density was obtained, and due to the insufficient density, only 1 g of the product could be put to practical use.

Means for Solving the Problems In order to solve the above-mentioned problems, the present invention is characterized in that molybdenum silicide powder is sealed in a sealing can and molded and sintered by a hot isostatic pressing (HIP) method. That is. Further, in the present invention, by using the sealing can in which Mo is sprayed in advance on the inner surface of the sealing can, it is possible to provide a target for a sputtering device with even higher purity and density.

Furthermore, it is also possible to use a case in which a high-melting-point full-flex plate of Mo, Nb, etc. is embedded on the inner surface of the enclosure.

In the present invention, since the LIIP method is used for shaping and sintering, there is an advantage that the target layer 1- can be formed into high density at a low temperature, has a uniform composition distribution, and is free from contamination with impurities.

In addition, in the present invention, a metal can stock consisting mainly of iron, which can be economically used as a sealing can, can be used. may cause damage or contamination of the can stock. Therefore, in the present invention, it is preferable to thermally spray Mo on the inner surface of the enclosed can in advance to prevent contamination of impurities from the can material and destruction of the can due to reaction with Si.

In addition, in the present invention, as the raw material powder, a mixed powder of molybdenum powder and silicon powder, molybdenum silicide powder, or a mixed powder of molybdenum silicide powder and silicon powder or molybdenum powder can be used, but molybdenum silicide powder is mainly used. Preferable results can be obtained from the viewpoint of uniformity of composition by using the raw material powder.

In general, Mo8 type LSI's 7"-1-ffi electrode film dino silicon content is 0 to 40% by weight (the composition is shown below)
does not indicate fJp%). That is, if the silicon-containing 18 chambers in the molybdenum silicide exceeds 40%, the resistance increases rapidly and the film becomes unsuitable as a gate electrode film.

Furthermore, if the silicon content is less than 30%, although the specific resistance/film thickness will be reduced, the adhesion with the substrate will be poor and the chemical stability will be poor, making it unsuitable as a gate electrode film. . For this reason, the silicon content in the gate electrode film is between 30 and 40%.
It is said that it is preferably between 35 and 37% (for example, Mo5iz is equivalent to 36.8% silicon).

As a result of extensive research, the present inventors found that there is an almost linear relationship between the silicon content in the gate electrode film and the silicon content in the molybdenum silicide target. It has been found that the silicon content in the gate electrode film is approximately several percentage points lower than the silicon content in the gate electrode film.

That is, the silicon content in the target corresponding to the required range of 30 to 40% for the silicon content in the gate electrode film is 35 to 43%, and these are MoSi,...
, Yu~MoSi, ,, corresponds to ヮ. In addition, a suitable silicon-containing layer in the gate electrode film is 35 to 37
The silicon content range in the target corresponding to 39~
40.6%, which is M OS i,,,s ”-
It corresponds to M OS i z,). For this reason, the composition of the molybdenum silicide Targera 1-, which is the object of the present invention, is particularly useful.

Further, the targera 1- obtained according to the present invention has a relative density of 90% or more. This is because if the relative density is less than 90%, the strength of the target will be insufficient, and it will become especially brittle, making handling inconvenient, and there is also a risk of cracking of the target during sputtering.

Example Hereinafter, the present invention will be explained in more detail based on examples.

Example 1 A molybdenum ingot with a purity of 99.98% and a molybdenum ingot with a purity of 9
9.9999% silicon ingot and MoSi2.
, (57.2% molybdenum, 42.8% silicon) and melted in a plasma arc melting furnace. The obtained alloy was pulverized in a vibrating pulverizer, and the obtained powder 1
6.4 parts by weight of silicon powder (similarly pulverized from the above silicon ingot) was added to the 00 suspended portion to obtain raw material powder for sintering.

Next, using this powder, hot pressing, pressureless sintering, H
It was sintered and formed using IP. Each condition at this time is as shown in Table 1.

Table 1 The properties of the shaped sintered body are shown in Table 2 and FIG. 1.

Table 2 It can be seen from Table 2 that the HIP molded product has a low level of impurities and a uniform density.

Figure 1 is a scanning electron micrograph showing the target surface after sputtering.Compared to conventional hot-pressed products and pressureless sintered products, the product of the present invention produced by the HIP method has the advantage of being free from fine particles that cause foreign matter during film formation. It is clear that this is hardly seen.

Example 2 Using the same raw material powder as used in Example 1 and under the same conditions as shown in Example 1, M was applied to the inner surface of soft W4 to a thickness of 0.2 mw1.
l-1 using a can sprayed with O and a can without sprayed Mo.
IP molded. In cans that were not sprayed with Mo, the can wall melted due to a eutectic reaction between the FQ in the can stock and 3i in the raw material powder, and was deformed to the point that it could not retain its shape, but in the case of cans that were sprayed with Mo, the Fe and Fe in the can stock were melted due to the Mo film. Since 3i in the raw material powder was separated, no reaction between Fe and 3i was observed, and the raw material powder was sintered into the desired shape.

The interface between the Mo sprayed can stock and the target is shown in Table 3. There was no intrusion of Fe, indicating that no reaction occurred between the target and the can stock.

Table 3 Example 3 Using the same raw material powder as used in Example 1 and under the same conditions as shown in Example 1, a 0.05 mm thick Mo
A can with a double-wound plate, a can with a double-wound Nb plate with a thickness of 0.01 mm, and a can with a single-wrap of a Mo plate with a thickness of 0.05 ml and a Nb plate with a thickness of 0.01 mm were used. HIP molded.

Fe in the can stock and Si in the raw material powder are separated by Mo plate or Nb plate.
is isolated, and the reaction between l”e and $1 is observed.
As shown in the table, [pF<'j Song (q) was obtained, and the can material and Kugut molded product after sintering could be easily peeled off, and no 7rJ staining by e was observed on the Targut 1- interface.

Effects of the Invention As described above, according to the present invention, a target made of a molybdenum silicide alloy suitable for forming a gate electrode insert of an NRI○S type LSI is provided. This Kugutsu 1~ has high strength and is easy to handle.

Moreover, according to the present invention, such a yugetto can be easily produced.

[Brief explanation of drawings]

FIG. 1 is a gold and pancreatic distance micrograph showing the spuck surface of the target. 'A 171, . 8) Sun, 71 ~ breath ♂, '< 6 () () hand
Continuing amendment
8゜July 17, 1985 (Chief of the Patent Office Black 1) Mr. Akihiro 1, Indication of the case 1985 Patent Application No. 31867 (2. Name of the invention Method for manufacturing targets for sputtering equipment 3, Make amendments) person
(Relationship with the case Patent Applicant Address February 2-1 Marunouchi, Chiyoda-ku, Tokyo Name (
508) Hitachi Metals Co., Ltd. 4, Agent 〒1
05 5,? Voluntary amendment without date of official order) 6.
By correction”? ) Number of inventions to be added None 7. Subject of amendment ■ Contents of amendment in "Detailed description of the invention" in the specification 1) "Contamination on can stock" on page 5, line 4 of the specification can be changed to "can stock" Contamination caused by 2) "Membrane pressure" on page 6, line 3 of the same book is corrected to "film thickness." 3) Correct the "medium silicon content" on the 14th line of the same page to "the silicon content in the middle is the silicon content in the molybdenum silicide target." Therefore, on page 14 of the same book, lines 14-15, "metal composition" is corrected to "scanning electron".

Claims (3)

[Claims] (1) By sealing the raw material powder in a sealing can and sintering it by hot isostatic press, it is made of molybdenum silicide with the composition MoSi_x (1.84≦x≦2.57) and has a relative density of 90%. A method for manufacturing a target for a sputtering apparatus, characterized by manufacturing a target as described above. (2) The method for manufacturing a target for a sputtering apparatus according to claim 1, wherein a Mo sprayed film is formed on the inner surface of the sealing can. (3) The method for manufacturing a target for a sputtering apparatus according to claim 1, wherein a high melting point metal plate such as Mo or Nb is embedded on the inner surface of the sealing can.