SOME PRELIMINARY-OBSERVATIONS OF THE RAPID THERMAL-OXIDATION OF POROUS SILICON, AND THE RAPID THERMAL NITRIDING OF OXIDIZED POROUS SILICON

Porous silicon, produced by the anodic oxidation of p-type single crys tal wafers of silicon in hydrofluoric acid/ethanol electrolytes has be en subjected to rapid thermal oxidation. For comparison purposes, and also to generate porous oxide for subsequent nitriding, other samples of porous silicon were subjected to conventional furnace oxidation. By TEM, EDS, and ESCA it was shown that the structures and compositions of the oxides produced by the two routes were similar. It was further demonstrated that oxidized porous silicon could be nitrided by rapid t hermal processing. The resulting structure, although still porous, sho wed a much diminished etching rate in hydrofluoric acid, compared to t he original oxide.