SI PILLAR FORMATION AND HEIGHT CONTROL BY FURNACE OXIDATION OF THE SI(111) SURFACE WITH ULTRA-SMALL SIN NUCLEI

Lithography-free Si pillar formation has been demonstrated by SIN nucl eation and subsequent selective oxidation steps, where nm-scale SiN nu clei thermally formed on the clean Si (111) surface were planned to be used as oxidation masks. In this experiment, dry oxidation at 800 deg rees C iii a furnace was employed as the oxidation step. As a result, Si pillars were successfully formed and the arrangement of the pillars was mostly random but partially characteristic, reflecting that of th e original SiN nuclei. It was found, however, that average pillar heig ht decreases with decreasing nitridation temperature, indicating the i mperfect mask ability of low-temperature SiN. This result is ascribed to the formation of SiON during oxidation, which has an inappreciable blocking effect for oxygen diffusion.