Refractory Metal Silicides

In this section, we will restrict our attention to the silicides of tungsten, molybdenum, tantalum and titanium. CVD WSi2 is currently being used commercially, and the other three have either been considered seriously or used to a limited extent. We will start with WSi2. 

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Deposition of Refractory Metal Silicides for VLSI Metallization, Technology, pp. 79-84 (Feb. 1989)... 

In the present chapter, we will review the nature of plasma-enhanced CVD (PECVD) films for a variety of applications. We will look at dielectrics (silicon nitride, silicon dioxide), semiconductors (polysilicon, epi silicon) and metals (refractory metals, refractory metal silicides, aluminum). There are many other important films (i.e., amorphous silicon for solar cells and TiN for tool harden-... 

At the same time, the fully doped polysilicon resistivity (LPCVD or PECVD) is proving inadequate for future generation IC devices, and interest is shifting to refractory metal silicides and/or refractory metals as replacements. Therefore, it is not clear how significant the development of such a new process will be for integrated circuit manufacture. There are other applications, however, where it may be better suited. 

The next three chapters review the deposition of thermally-induced dielectric films (Chapter 3) and metallic conducting films (Chapter 4), as well as plasma-enhanced films of either type (Chapter 5). The many chemical systems employed to create these films are considered, and the nature of the resulting films is presented. Films studied are silicon dioxide, silicon nitride, polysilicon, epitaxial silicon, the refractory metal silicides, tungsten and aluminum. 

Properties of refractory metal silicides and refractory metals... 

Bernard C, Madar R, Paulear Y (1989) Chemical vapour deposition of refractory metal silicides for VLSI metallization. Solid State Technol 32 79-84... 

REFRACTORY METAL / SILICIDE MULTIPHASE SYSTEMS FOR HIGH TEMPERATURE STRUCTURAL APPLICATIONS... 

The refractory metal silicides have been used for many years to protect refractory metals from oxidation in very high temperature, but short duration applications [121], These coatings have been highly successful but their use in applications which require long term stability have been limited by problems with accelerated oxidation and... 

In general (Table 14.1), silicides reacting at low temperatures (quasi-noble metals) and forming as first reacted phase metal-rich compounds (MejSi) exhibit a behavior characterized by a time dependence of the growth [26]. In turn, the thickness of refractory metals silicides, which require higher temperatures to react. 

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