| 摘要 |
PROBLEM TO BE SOLVED: To suppress the formation of recessed and projecting sections on the internal surfaces of trenches. SOLUTION: A plurality of SiO2 buried layers having trench filling-up shapes is formed (steps S10, S14, S18) and n- and p-type SiC epitaxial layers and an n-type SiC source areas are formed in the circumferences of the buried layers (steps S12, S16, S20, and S22). Then a trench is formed from the surface of the n-type source are 20 to the n-type epitaxial layer 12 by performing hydrofluoric acid etching on the buried layers (step S24). Since SiC is hardly etched as compared with SiO2 in the step S24, the SiC of the source area 20 is little etched and, accordingly, the formation of recessed and projecting sections on the internal surfaces of the trench can be suppressed.
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