| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a trench-gate-type semiconductor device having high flatness of a gate electrode, with a high-dielectric film as a gate insulating film. <P>SOLUTION: A semiconductor device comprises a semiconductor layer 1 of a first conductive type, a first semiconductor layer 2 of a first conductive type, and a second semiconductor layer 3 of a second conductive type. An oxide film 5 containing at least any of aluminium and yttrium covers the second semiconductor layer 3 exposed on the sidewalls of a trench that penetrates through the second semiconductor layer 3 and reaches the inside of the first semiconductor layer 2. A protective layer 6 is formed on the oxide layer 5 while facing the second semiconductor layer 3. A gate insulating film 7 is constituted from the oxide film 5 and the protective layer 6. A gate electrode 8 composed of n-type polysilicon is embedded in the trench while directly bonded to the gate insulating film 7. Third semiconductor layers 10 of a first conductive type contacting the gate insulating film 7 are selectively disposed on the surface of the second semiconductor layer 3. <P>COPYRIGHT: (C)2012,JPO&INPIT |
