Highly efficient oxidation of silicon at low temperatures using atmospheric pressure plasma

Silicon oxide (SiO2) layers were formed with initial oxidation rates in the range of 6.2-14.1 nm/min in the temperature range of 150-400 degrees C by oxidizing Si(001) wafers. Such a high-rate and low-temperature oxidation was realized by using a stable glow He/O-2 plasma excited at atmospheric pressure by a 150 MHz very high-frequency power. Increasing the temperature led to both the higher oxidation rate and the better quality of SiO2 and SiO2/Si interface. The oxidation at 400 degrees C showed an interface trap density of 6.2x10(10) eV(-1) cm(-2), which is considerably lower than that in a radical oxidation process using low-pressure He/O-2 plasma at the same temperature. (c) 2007 American Institute of Physics.