Silicon Epitaxial Layers with Abrupt Interface Impurity Profiles

Silicon epitaxial layers of good quality have been deposited on silicon substrates by the pyrolysis of silane at low temperatures. Studies to minimize the degradation of the impurity profile of an epitaxial silicon layer caused by various sources or processes are reported. Auto doping and system doping during deposition have been minimized by using techniques such as sealing the backsides of the substrates, sealing the susceptor, and using two‐temperature cycle depositions. Impurity profiles of the layers deposited by the above methods are compared with the profiles of the layers obtained from more conventional deposition conditions.