METHOD OF PROVIDING A BORON DOPED REGION IN A SUBSTRATE AND A SOLAR CELL USING SUCH A SUBSTRATE

摘要

Method of providing a boron doped region (8, 8a, 8b) in a silicon substrate (1), includes the steps of: (a) depositing a boron doping source (6) over a first surface (2) of the substrate (1); (b) annealing the substrate (1) for diffusing boron from the boron doping source (6) into the first surface (2), thereby yielding a boron doped region; (c) removing the boron doping source (6) from at least part of the first surface (2); (d) depositing undoped silicon oxide (10) over the first surface (2); and (e) annealing the substrate (1) for lowering a peak concentration of boron in the boron doped region (8, 8a) through boron absorption by the undoped silicon oxide. The silicon oxide (10) acts as a boron absorber to obtain the desired concentration of the boron doped region (8).