| 摘要 |
PURPOSE:To prevent a concentration of current due to the parasitic bipolar transistors in a power MOSFET and to enhance the withstand voltage of the power MOSFET by a method wherein the ballast resistors consisting of a polycrystalline silicon film and so forth are inserted in the source regions. CONSTITUTION:An n type silicon substrate 1 is provided with the drain electrode film on its bottom surface through a high-concentration n<+> type layer 2. Gates 5 consisting of a polycrystalline silicon film and so forth are formed on the surface of a p type layer 3 through insulating films 4 and n<+> type diffusion layers 6, which are used as the sources, are formed in parts of the surface of the p type layer 3 using the gates 5 as masks. Ballast resistors 7, which are connected to the sources, respectively consist of a polycrystalline silicon film and are extendly provided on the gates 5 through the insulating films 4. A part of a source electrode 10 is connected to the surface of the p type layer 3 and the other parts thereof are connected to the ballast resistors 7 through the through holes of SiO2 films 9, which are formed by a CVD method. |
