| 摘要 |
PURPOSE:To decrease manufacturing processes in number by a method wherein a coating protective film is formed without exposing a P-N junction and an uppermost nitride film is utilized as a mask when a contact hole is formed. CONSTITUTION:An N<->-type epitaxial 10 is formed on a wafer 1 for the formation of a buried gate region 3. An N<+>-type semiconductor layer 4 is formed on the surface of the epitaxial layer 10, thereafter mesa grooves 11 and 12 are provided to both the primary faces so as to make their bases deeper than a P-N junction, so that a water 13 provided with mesa grooves can be obtained. An oxidation protective film 20 is formed onto the mesa grooves 11 and 12. Thereafter a patterning is performed through a resist 21, where the part on which a contact hole is to be formed is excepted from the patterning, and a nitride film 22 is formed through a spattering or the like. Then, a lift-off is excecuted, a nitride film 22 is formed on the oxide film 21 except the part where the contact hole is to be provided, and annealing is performed. The oxide film 21 is subjected to etching using the nitride film 22 as a mask so as to form a contact hole 23. |
