Selective epitaxial growth using disilane and hydrogen/oxygen gas in low-pressure chemical-vapor deposition

Abstract

Without a chlorine source, the use Of Si(2)H(6)/H(2) chemistry for selective silicon epitaxy in a low-pressure chemical-vapor deposition reactor in the temperature range 600similar to710 degreesC under an ultraclean environment was investigated. As a result of ultraclean processing and hydrogen passivation during heating, an inherent incubation period for SiO(2) and a low-temperature selective epitaxy growth for Si could be achieved without addition of HCl. In order to extend the incubation period, we kept high-pressure (200 mTorr) H(2) environment without Si(2)H(6) gas for a few minutes after the first incubation period. Also, oxygen gas (I X 10(-7) Torr) was introduced for 10 see just before the end of the first incubation time so that the addition of oxygen could etch Si nuclei in the silicon dioxide. To the confirm the selectivity, we investigated the microstructures of the surfaces of both bare Si and SiO(2) by using the scanning electron microscope image of a 1000 Angstrom SiO(2)- patterned Si wafer.