Chemical vapor deposition and deep level analyses of 4H-SiC(11 bar 2 0)

Specular 4H-SiC layers have been homoepitaxially grown on 4H-SiC(11 bar 20), parallel to the c axis (<0001>), by chemical vapor deposition at 1500 degreeC. An x-ray diffraction analysis has revealed that a lattice-mismatch strain between n- epilayers and n+ substrates could be minimized by introducing n-type buffer layers. The donor concentration of unintentionally doped epilayers could be reduced down to 1x1014cm-3 under a C-rich 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 3.8x1012cm-3. The capture cross section of the deepest trap, the Z1 center, at high temperatures has been determined. [copyright] 2001 American Institute of Physics