Full Title Manufacturing of Sputtering Targets of Pure Refractory Metal Silicides Tech Area / Field

• INF-ELE: Information and Communications / Microelectronics and Optoelectronics
• MAT-CER: Materials / Ceramics
• PHY-SSP: Physics / Solid State Physics
• CHE-SYN: Chemistry / Basic and Synthetic Chemistry

Brief Description of Technology
Refractory metal silicides are very promising materials for low-resistant contacts, gate electrodes and interconnections in microelectronics devices. The specific electrical resistivity of refractory metal silicides is their most important criteria recommending them as choice material for VLSI technology. At the moment, two main technologies to produce silicide thin films are used. The first one consist of the deposition of thin layers of metal and silicon followed by high temperature annealing and final MeSi-layers formation. The second technology consists of the use of targets from refractory metal silicides during magnetron sputtering. Usually, methods of powder metallurgy are used to prepare such a silicide targets. However, this technology does not provide a desirable level of purity and leads to the low quality of silicide films. Moreover, such powder silicide targets have a low index of heat conductivity. This leads to limited deposition rates which increases the probability of film contamination.

We have developed a brand new technique for the production of targets from stoichiometric silicides of refractory metals by means of melting pure initial materials in a vacuum or noble gas atmosphere, followed by casting them into cooled mold of a special shape. It is very difficult to use other techniques for melting silicides due to the high difference in vapor pressure (i.e. W and Si).

Manufactured targets from tungsten and cobalt di-silicides (WSi₂, CoSi₂) have been successfully used for the preparation of thin high-quality di-silicide films, using both magnetron sputtering and laser ablation. The specific electric conductivity values for di-silicide films of 20 and 50 mW´cm were achieved for CoSi₂ and WSi₂, respectively. These values are at least one order of magnitude lower when compared to di-silicide films manufactured with the use of targets prepared by the sintering of di-silicide powders.

Legal Aspects
There are a few patens of the former USSR on some parts of the unit used to prepare di-silicide targets.

No Russian patents.

Special Facilities in Use and Their Specifications
None in this research.

Scientific Papers
V.G. Glebovsky and E.A. Markaryns. Thin film metallization by magnetron sputtering from highly pure molybdenum targets. J. Alloy and Compounds, 190 (1993) 157-160.

Yu.M. Shulga, V.G. Glebovsky, Yu.Ch. Dulinets, V.I. Rubtsov, Yu.G. Borodko. Electron energy-loss spectroscopy as an analytical tool in the study of TiSi₂/Si interfaces. Materials Letters, 15 (1993) 325-330.

V.G.Glebovsky, R.A.Oganyan, S.N. Ermolov, E.D. Stinov, E.V. Kolosova. Preparation of tungsten disilicide thin films by laser evaporation Thin Solid Films, 239 (1994) 192 -195.

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