JPS61116835A - Sputtering target for lsi or very lsi electrode wiring material - Google Patents

Abstract

PURPOSE:To obtain high purity and ultra-fine crystal grain by adding at least a kind of alloyed element of Mo, W, Ti, Ta, Zr or Pt and Si in the 0.1-8.5wt% to the base metal of said Mo, W, Ti, Ta, Zr or Pt. CONSTITUTION:When Si is added to Mo as an alloy element, as an example, and it is melted, Si exists within the alloy as a silicate, fine crystal organization in grain diameter of 0.5-1mm can be obtained. When it is used for sputtering target, dielectivity of sputtering is uniform and mechanical workability is also good. The similar effect can also be obtained by adding W (added as WSi) and Si to the base material Mo and then melting them. However, amount of addition of alloyed component is limited to 0.1-8.5wt%. If it is under 0.1wt%, it becomes difficult to obtain uniform fine crystal grain and mechanical working becomes also very difficult. Therefore, amount of addition should be set as small as possible and it is preferable to set the upper limit to 8.5wt%. In this case, initial discharge is stabilized and distribution of film thickness is also improved.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a snow ξ tsuttering target for LSI or ultra-L8I electrode wiring material having a microcrystalline structure.

Conventional technology Conventional 1 For example, this Zensu/e Tsuta ring molybdenum target is manufactured by pressing high-purity molybdenum powder, but the molybdenum sintered body manufactured by the pressing method is powdery because molybdenum itself is active. The surface is easily contaminated by oxygen, etc., and gas components are stored in the sintered body.
It is known that this results in a target with low purity.

Therefore, in order to obtain molybdenum of high purity, electron beam melting or melting in a reducing atmosphere is usually performed. However, as is well known, the higher the purity of the metal, the larger the crystal grains of the molten product. Furthermore, it is generally known that subsequent processing such as forging is extremely difficult for ingots with large crystal grains.

Problems to be solved by the invention On the other hand, the current situation requires target materials with complex shapes.
If the crystal grains are large, there are problems such as easy cracking from the grain boundaries when machining as a target material, and when performing snog tsuttering using a target with large crystal grains, differences in the crystal grains may occur. It is known that due to the orientation, a stagnation film having different properties is formed, which also affects the quality of the film.

Means for Solving the Problems The present inventors have established a method of achieving high purity and miniaturizing crystal grains in order to solve the various drawbacks of the conventional methods as described above.

The present inventors melted a material containing high-purity silicon in the form of silicide in high-purity molybdenum, and were able to obtain Mo-8+ in the form of fine crystals despite its high purity. I discovered that. Furthermore,
Combinations of base metals other than molybdenum and silicon include tungsten, titanium, zirconium, tantalum, or platinum as the base metal, and as the additional association element.

Preliminary statement - Seven types of base metals and silicon were confirmed as a result of experiments.

Therefore, the gist of the present invention is as specified in the claims, and specific examples of the present invention will be described in detail below.

For example, when molybdenum (Mo) is melted by adding silicon (Si) as Zenghenyuanzi, silicon exists in the Molybdenum as a silicate, and the melted molybdenum-silicon alloy has a desired degree of microcrystalline structure. presents.

When used as a sputtering target, the sputtering direction is uniform and the machinability of desired shapes is excellent.

In addition, molybdenum is used as the base metal, and tungsten (added as tungsten silicate) is used as the additive component.
When silicon was added and melted, a fine crystal structure was obtained, and the same results as with Mo-8i were obtained.

The amount of the alloying component added is 0. The reason for limiting it to /, J', and J'jukei is as follows. Si into MO
The solid solubility limit of / at 100°C is about 7 times J.

When the temperature is below 1000°C, the solid solubility decreases rapidly.

Therefore, the effect of grain refinement can be expected to be sufficient just by adding a small amount of 8i. However, according to fruit M.1, if the amount of 8i added is less than 0.1% by weight, it is difficult to uniformly refine the crystal grains and variations occur in the grain size.

Therefore, the amount of Si added is 0. /Must be above the weight limit. Also, a monster of Mo and Si, M o 3 S
i and Mo3Si2 are generated, making machining very difficult. Therefore, it is necessary to reduce the amount of Si added to obtain the effect of crystal refinement. As a result, the upper limit of the amount of Si added is preferably r3 heavy.

Example What is the weight ratio of Mo powder and Si powder? They were mixed in the ratio P: / and subjected to tempering treatment to prepare a Mo mixed powder.

This mixed powder was shaped into a bottom shape using a press mold, and then purified and melted to obtain a Mo ingot with a small crystal grain size.

This ingot could easily be subjected to conventional machining.

The grain size of the Mo ingots according to the conventional method and the present invention is io, while the latter is 0. j −/, and //10
We were able to refine the structure to the following.

FIG. 1 is a cross section of a conventional Mo ingot, and FIG. 2 is a schematic diagram showing crystal grain sizes in a cross section of an ingot of the present invention.

Effects of the Invention The sputtering characteristics of the ingot of the present invention were improved in the point F below.

(a) The time for buri sputtering is shortened.

Initial discharge stabilized.

(b) Film thickness distribution was improved by 2 to 3%.

[Brief explanation of drawings]

1! 2 is a schematic diagram showing the crystal grains of a conventional Mo ingot, and FIG. 2 is a schematic diagram showing the crystal grains of the Mo ingot of the present invention.

Claims (1)

[Claims] Addition of 0.1 to 8.5% by weight of at least/some alloying elements of Mo, W, Ti, Ta, Zr, Pt and Si to a base metal consisting of Mo, W, Ti, Ta, Zr or Pt. A sputtering target for LSI or VLSI electrode wiring material having a microcrystalline structure.