| 摘要 |
PURPOSE:To reduce the DC resistance of the channel layer of a double-diffusion type MOSFET and prevent bipolar activity without deteriorating other characteristics by a method wherein the channel layer is formed thinner under a gate and thicker at other part. CONSTITUTION:An N<+> type drain diffused region 2 and a P<+> type channel contact diffused region 3 are formed on a surfce of an N type silicone wafer 1 and an oxide film 14 is remained on each region. Then an oxide film 14 of 5,000-1,000Angstrom thickness is formed by a thermal oxidizing method and a polysilicone film 15 is grown to the thickness approximately 4,000Angstrom on the oxide film 14 by a thermal decomposition method. Then the polysilicone 15 is patterned and boron is ion-injected using the patterned polysilicne 15 as mask, so that a channel layer 16 is formed. And a source fiffused layer 17 is formed by side-etching the oxide layer 14 and diffusing phosphorus by a gaseous phase diffusion method. The thickness of the channel layer 16 under the gate is reduced by th side-etched amount. |
