| 摘要 |
PROBLEM TO BE SOLVED: To provide a semiconductor device in which the reliability of an insulating film formed on the inwall of a trench is higher than conventional, and a method for manufacturing the semiconductor device. SOLUTION: In a method for manufacturing a power MOS FET having a trench gate electrode, trenches 4 are formed on a semiconductor substrate 3 constituted by forming an n<SP>-</SP>-type drift layer 2 on an n<SP>+</SP>-type substrate 1. Then a gate insulating film 5 is formed on the inwall of each trench 4 and a gate electrode 6 is formed in the trench 4 through the gate insulating film 5. Then an oxide film is formed on the surfaces of the gate electrodes 6 and the semiconductor substrate 3. In order to improve the reliability of the gate insulating films 5, high temperature annealing treatment is performed in an inert atmosphere at 1170°C for instance. Then p-type areas 7 to be channels, n<SP>+</SP>-type areas 8 to be sources and body p-type areas 9 are formed on the surface layer of the semiconductor substrate 3 and an inter-layer insulating film 10, a metallic film 11 to be a source electrode, and so on are formed. COPYRIGHT: (C)2004,JPO&NCIPI
|
