Surface passivation of silicon based wafers

摘要

The surface recombination velocity of a silicon sample is reduced by deposition of a thin hydrogenated amorphous silicon or hydrogenated amorphous silicon carbide film, followed by deposition of a thin hydrogenated silicon nitride film. The surface recombination velocity is further decreased by a subsequent anneal. Silicon solar cell structures using this new method for efficient reduction of the surface recombination velocity is claimed.

主权项

1. A method for surface passivation of silicon based semiconductors, wherein the method comprises:
cleaning the surface of the semiconductor that is to be passivated, removing an oxide layer on the surface of the semiconductor that is to be passivated, introducing the cleaned surface of the semiconductor into a plasma enhanced chemical vapor deposition chamber, depositing a 10-100 nm thick amorphous silicon passivation layer directly on the surface of the semiconductor that is to be passivated by use of SiH4 as a precursor gas at about 250° C., depositing a 70-100 nm thick silicon nitride passivation layer on top of the deposited amorphous silicon passivation layer by use of a mixture of SiH4 and NH3 as precursor gases at about 250° C., and finally annealing the wafer with the deposited passivation layers at a temperature of about 500° C. for four minutes.