Characteristics of Two‐Step Continuous Deposition of In Situ Doped and Undoped Polycrystalline Silicon

Abstract

The dosage redistribution and interfacial structure of a polysilicon film deposited by a novel two‐step continuous deposition of in situdoped and undoped polycrystalline silicon is described. A tungsten silicide film is deposited on the composite layers which then makes contacts with the p− substrate. The depth profile of phosphorus is uniformly redistributed after 850°C, 60 min and 900°C, 30 min annealing and is related to the concentration of oxygen. The phosphorus concentration in polysilicon and the junction depth become smaller as the thickness of in situ doped polysilicon gets thinner. The interfacial oxide is locally epitaxially broken up after this thermal cycle.