Epitaxial growth of SiC in a single and a multi wafer vertical CVD system: a comparison.

First results about a new system suited for epitaxial growth on six 2’ SiC-wafers at a time are presented in comparison to typical results in a single wafer CVD system. As expected, the multi wafer system today shows a by one order of magnitude higher background impurity level (≤ 1015 cm−3 compared to ≤ 1014 cm−3). On the other hand, the doping homogeneity is already very encouraging. The total variation on a 2 inch wafer is less than ± 20% at about 1*1016 cm−3. The surface of the epitaxial layers is very smooth with a typical growth step height of 0.5 nm (4H 8° off orientation). First measurements on Schottky diodes show low leakage current values indicating low point defect density in the epitaxial layers.