Development of 4H-SiC epitaxial growth technique achieving high growth rate and large-area uniformity

A verfical hot-wall epi-reactor that makes it possible to simultaneously achieve a high growth rate and large-area uniformity has been developed. A maximum growth rate of 250 mu m/h is achieved with a mirror-like morphology at 1650 degrees C. Under a modified epi-reactor setup, a thickness uniformity of 1.1% and a doping uniformity of 6.7% for a 65-mm-radius area are achieved while maintaining a high growth rate of 79 mu m/h. A low doping concentration of similar to 1 x 10(13) cm(-3) is obtained for a 50-mm-radius area. The low-temperature photoluminescence (LTPL) spectrum shows the predominance of free exciton peaks with only few impurity-related peaks and the L, peak below detection limit. The deep level transient spectroscopy (DLTS) measurement for an epilayer grown at 80 mu m/h shows low trap concentrations of Z(1/2): 1.2 x 10(12) and EH(6/7): 6.3 x 10(11) cm(-3). A 280-mu m-thick epilayer with a RMS roughness of 0.2 nm and a carrier lifetime of similar to 1 lis is obtained. (C) 2008 The Japan Society of Applied Physics.