Semiconductor substrate homopolar epitaxial layer deposition process - coating sides and rear of substrate to prevent corrosion, esp. for high resistance transistor mfr.

摘要

The process has the rear face of the highly doped semiconductor substrate and its side faces initially coated with a thermic silicate layer, followed by a silicon nitride layer. The formation of the epitaxial layer may be followed by a diffusion stage using a dopant with the opposite conductivity type within the epitaxial layer, the former double layer retained to act as the diffusion mask. Pref. the first layer has a thickness of approximately 0.2 microns and the thickness of the second layer is approximately 0.1 microns. The substrate is placed on a silicon carbide support with both heated during the process by IR or HF radiation.