Chemical vapor deposition and deep level analyses of 4H-SiC(11(2)over-bar0)

Specular 4H-SiC layers have been homoepitaxially grown on 4H-SiC(11(2) over bar0), parallel to the c axis ([0001]), by chemical vapor deposition at 15 00 degreesC. An x-ray diffraction analysis has revealed that a lattice-mism atch strain between n(-) epilayers and n(+) substrates could be minimized b y introducing n-type buffer layers. The donor concentration of unintentiona lly doped epilayers could be reduced down to 1 x 10(14) cm(-3) under a C-ri ch growth condition. Through isothermal capacitance transient spectroscopy measurements, three acceptor-like traps with activation energies of 0.27, 0 .32, and 0.66 eV have been detected with a total trap concentration as low as 3.8 x 10(12) cm(-3). The capture cross section of the deepest trap, the Z(1) center, at high temperatures has been determined. (C) 2001 American In stitute of Physics.