Thermal oxidation of (0001) 4H-SiC at high temperatures in ozone-admixed oxygen gas ambient

The method of oxidation by atomic oxygen has been developed for gate oxide formation in SiC metal-oxide-semiconductor (MOS) devices. Ozone (O-3)-admixed oxygen (O-2) gas is introduced into the cold-wall oxidation furnace, where atomic oxygen in a ground state is formed by thermal decomposition of O-3 molecules at elevated sample temperatures. The growth rate of oxide in the O-3-admixed gas shows a maximum at around 666.4 Pa and 950-1200 degreesC, whereas the rate in pure O-2 gas is negligible below 6664.5 Pa. Interface trap density (D-it) of the MOS capacitors fabricated using atomic oxygen strongly depends on the oxidization temperature; oxidation at 1200 degreesC results in significant reduction of D-it in comparison with that at 950 degreesC. (C) 2003 American Institute of Physics.