| 摘要 |
An epitaxial silicon layer may be deposited on a monocrystalline silicon body by Chemical Vapor Deposition at reduced pressure and low deposition temperature by a method which includes cleaning the substrate within the CVD reactor. The cleaning within the reactor is achieved solely by applying a heat pulse by heating the substrate to a cleaning temperature above 1000 degrees Celsius for a time in the range of from 15 seconds to 90 seconds. In one example deposition of the layer is started by introducing silicon carrier gas not more than 15 seconds before the end of the heat pulse and at the end of the heat pulse the substrate temperature is allowed to fall to a desired deposition temperature between 650 degrees Celsius and 800 degrees Celsius for silane and 800 degrees Celsius and 875 degrees Celsius for trichlorsilane. In another example the carrier gas is introduced before the start of the heat pulse and the deposition is terminated by allowing the substrate temperature to fall at the end of the heat pusle to a temperature below the minimum at which epitaxial deposition occurs. Preferably radiant heating is used to heat the substrate to the cleaning temperature, and the method may be carried out in an existing radiantly heated CVD reactor. The method allows the deposition of layers of low transition depth (D) shown by SIMS profile (3) of the layer (S-I) and doped substrate.
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