Nonsilicide

Nonsilicide is a term used in materials science and solid-state chemistry to denote compounds or materials that do not form metal silicides or do not contain silicon in a silicide state. The expression is not widely standardized, and its meaning can vary with the context, often contrasting nonsilicide materials with silicide phases that are commonly used in electronic devices.

In semiconductor technology, silicides are formed when silicon reacts with certain metals to reduce contact resistance at interfaces. Nonsilicide materials, by contrast, are those that do not form silicon-containing silicide phases under typical processing conditions. They are often chosen for roles such as diffusion barriers, diffusion-stop layers, protective coatings, or dielectric and insulating layers, where a silicide behavior would be undesirable.

Common examples of nonsilicide materials include metal nitrides such as titanium nitride and tantalum nitride, metal oxides such as aluminum oxide and hafnium oxide, and other non-silicon-containing compounds like certain carbides and borides. These materials are valued for properties such as thermal stability, chemical inertness, electrical insulation or controlled conductivity, and resistance to interdiffusion with silicon or silicon-containing devices.

It is important to note that the term nonsilicide can be ambiguous in literature, particularly when silicon-containing compounds that are not silicides (for example silicon carbide or silicon nitride) are discussed. In such cases it is helpful to specify composition and context to avoid confusion with true metal silicides.

See also: Silicide, Silicon chemistry, Diffusion barrier, Semiconductor device.