Hydrogen peroxide in basic solution to clean polycrystalline silicon after phosphorous diffusion

摘要

The method for providing a cleaned doped polycrystalline silicon surface involves providing a polycrystalline silicon body. The body is uniformly doped with a phosphorous impurity from a phosphorous vapor source, such as phosphorous pentoxide. The silicon oxide surface layer is removed from the doped polycrystalline silicon surface formed during the doping with a hydrofluoric acid solution. An important cleaning step of the doped polycrystalline silicon surface is now accomplished with a basic solution of hydrogen peroxide. The highly dense integrated circuit device process can now proceed with any desired patterning of the polycrystalline body or layer without the yield problems of the past.