GaN growth on (30(3)over-bar8) 4H-SiC substrate for reduction of internal polarization

We have proposed a novel solution with a use of a (30 (3) over bar8) 4H-SiC substrate for the reduction of internal polarization in the GaInN QWs. With changing the pressure at the initial stage of the nitride growth, two crystallographic orientations of the nitride layers could be switched. When the growth pressure was as high as 1013 hPa, the c-axis of the GaN is 54.7 degrees tilted from the surface plane. On the other hand, the GaN having 7 degrees tilted c-axis was dominant with the growth pressure of 100 hPa, where there is a relationship of SiC 0001) H GaN (10 (1) over bar1). We fabricated a LED on the (30 (3) over bar8) 4H-SiC substrate, where the c-axis orientation of 54.7 degrees is tilted from the surface plane. The blue shift of the peak wavelength with increasing injection current was confirmed to be smaller than that of conventional LED grown along the c-axis on sapphire substrate. This small blue shift may be certain evidence that the GaInN active layer has small internal field as we expected. (c) 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.