SELECTIVE FORMATION OF LUMINESCENT POROUS SILICON BY PHOTOSYNTHESIS

Selective patterning of luminescent porous silicon was achieved by a p hotosynthesis method. Porous silicon was selectively formed on boron-d oped p+ regions patterned on a n-type silicon surface with spatially u niform photoirradiation. Porous silicon stripes formed on 7-mum-wide p + stripes exhibited a clear visible photoluminescence image with the s ame dimension. The mechanism of the selective formation is discussed f rom the viewpoint of how photogenerated holes are accumulated. The res olution limit in the present method is given by the sharpness of the p otential distribution at the p-n junctions, i.e., the widths of deplet ion layers, which reduce for highly doped p-n junctions.