Method and apparatus for formation of in-situ doped amorphous semiconductor film

Abstract

A LPCVD (Low Pressure Chemical Vapor Deposition) process is used for formation of a doped amorphous semiconductor film with in-situ doping of the semiconductor film on a plurality of semiconductor wafers with reduced defects and with predictable electrical characteristics. The plurality of semiconductor wafers are placed in a reaction chamber. The pressure within the reaction chamber is set to be less than approximately 1.0 Torr, and the temperature within the reaction chamber is set to a predetermined temperature in a range of from about 500° Celsius to about 550° Celsius. A semiconductor film reactant and a dopant reactant are introduced into the reaction chamber through at least two gas inlets. Each gas inlet is disposed on a respective location of the reaction chamber near the pluralty of semiconductor wafers, and each gas inlet carries both of the semiconductor film reactant and the dopant reactant. The doped amorphous semiconductor film is formed from the semiconductor film reactant with in-situ doping from the dopant reactant on the plurality of semiconductor wafers in a LPCVD (Low Pressure Chemical Vapor Deposition) process. With the at least two gas inlets carrying the semiconductor film reactant and the dopant reactant in the LPCVD (Low Pressure Chemical Vapor Deposition) process, the doped amorphous semiconductor film deposited on the plurality of semiconductor wafers has more predictable and uniform electrical characteristics such as sheet resistance across a semiconductor wafer.