Nitridation of silicon and other semiconductors using alkali metal catalysts

Abstract

Nitride layers are formed on semiconductor substrates utilizing alkali metals as catalysts. The surface of the semiconductor substrate first has a thin layer of an alkali metal deposited thereon and then is exposed to nitrogen from a nitrogen source at temperatures and pressures sufficient to grow a nitride layer, which will generally occur at lower temperatures than required for nitride formation by conventional processes. The surface is then annealed and the catalyst removed by heating at moderate temperatures, desorbing the catalyst and leaving a nitride layer on the surface of the substrate which is uncontaminated by the alkali metal catalyst. The process is particularly suited to the formation of nitride layers on silicon utilizing essentially a monolayer of the alkali metal such as sodium. After formation of the nitride, heating of the substrate drives off essentially all of the catalyst at temperatures sufficiently low that the silicon substrate is not impaired for further processing steps, such as the formation of microelectronic devices.

Dependencies are inferred from the claim text.