A Hot‐Wall Low‐Pressure Reactor for Selective Silicon Epitaxy: Reactor Design and Experimental Results

Abstract

A tubular hot‐wall silicon epitaxial reactor operating at reduced pressure is described. It has been constructed by modifying a commercial low‐pressure chemical vapor deposition furnace and is proposed as a potentially cost‐effective means of depositing selective epitaxial silicon layers. Defect‐free selective epitaxial layers are grown at temperatures as low as 820°C, following a bake in hydrogen at 900°C. The lower growth rate in a hot‐wall system is found to cause abrupt dopant transitions to be less steep by factor of two in comparison to a cold‐wall reactor operating at the same temperature. The two‐order transition width for growth at 850°C is 0.07 μm for antimony n+ substrates and 0.26 μm for p+ boron substrates. Metal oxide semiconductor devices fabricated on the epitaxial layers are indistinguishable from devices fabricated on standard substrates.