The influence of annealing conditions on the efficiency of phosphorous gettering in CZ-Si for solar cell applications

摘要

The effect of the annealing ambient on the efficiency of the phosphorous gettering process for Czochralski (CZ) silicon waters is investigated in this paper. Phosphorous is diffused from a POCl_3 source at different temperatures into single-crystal p-tyupe silicon wafers having a resistivity of around 1 ohm/cm. This is followed by an additional heat treatment in either oxidizing (wet and dry oxide) ro in inert (argon) ambient. The laser microwave photoconductivity decay method is used to monitor the changes in the mionority carrier lifetime after the phosphorous diffusion and the subsequent annealing. Furthermore, solar cells are fabricated on the treated samples in order to corelate the lifetime measuremnts with the illuminated I-V characteristics of the cells.