| 摘要 |
A semiconductor device (such as a MOSFET) can prevent a lowering in the reliability of a gate insulating film and can cope with a finer trench pattern. The MOSFET has a plurality of trenches penetrating a p−-type doped region and a gate electrode formed on the interior surface of each trench with a silicon oxide film (gate insulating film) interposed. The gate electrode is embedded inside the trench such that the upper surface of the former is located above the p−-type doped region, and includes a polysilicon layer facing the p−-type doped region with the silicon oxide film sandwiched therebetween and a low-resistance layer formed on the upper surface of the polysilicon layer and having a lower electrical resistivity than that of the polysilicon layer. An SiN film is formed between the silicon oxide film and the side surface of the low-resistance layer above the p−-type doped region. |
