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Checker-Board Carbonization for Control and Reduction of the Mean Curvature of 3C-SiC Layers Grown on Si(100) Substrates

Due to the large lattice and thermal expansion mismatch between SiC and Si, the epitaxy of a SiC layer on a Si substrate results in a highly defected layer and a strong bow of the wafer. The defects are not detrimental in many applications but the bow can be. It has been shown that, depending on the carbonization conditions, it was possible to obtain compressively or extensively stressed SiC layers, but with a transition domain which is so narrow that in practice unstressed SiC layers cannot be obtained on a silicon substrate. We have used a checker-board like SiO2 patterning to perform selective carbonization of the substrate, half area being in compression and half area in tension. After growth of several μm thick 3C-SiC layers, strong reduction of the mean bow was observed so that homogeneous surface polishing was possible on a whole 35 mm diameter epilayer.