Difference of Near-Interface SiO_2 Structures between O_2-Oxidation and H_2O-Oxidation of 4H-SiC (0001) and Its Impact on MOS Interface Characteristics

摘要

The effects of the selection of oxidant species, i.e. O_2 or H_2O on metal-oxide-semiconductor (MOS) interface properties on both 4H-SiC (0001) Si-face and (000-1) C-face were systematically investigated from the viewpoints of near-interface oxide microscopic structures, as well as those of electrical characteristics of MOS capacitors. As the possible origins of the significantly different MOS characteristics between dry and wet-oxidized interfaces, the differences in the strained structure of near-interface SiO_2 were indicated. The important roles of both oxygen partial pressure in wet-oxidation ambient and oxidation temperature to control the MOS interface characteristics were also discussed.