| 摘要 |
PURPOSE:To obtain a minute buried layer having low resistance by selectively forming a semiconductor buried layer containing a high-concentration impurity onto an oxide film on a semiconductor layer. CONSTITUTION:A drain region 13 is buried into a semicoductor substrate 11, and a thermal oxide film 15 and a silicon nitride film 16 are shaped onto the substrate 11. An oxide film 17 is formed. The films 15, 16 are removed, and an oxide film 18 and a polycrystal silicon layer 19 containing the high-concentration impurity are shaped. The layer 19 is processed rectangularly, and the film 18 is etched while using the layer 19 as a mask. The substrate 11 is oxidized, and an oxide film 21 is molded onto a gate region 20 consisting of the layer 19. These are immersed into a buffer HF aqueous solution, and a thermal oxide film 21 is left only around the region 20. A single crystal silicon layer 23 is formed, and a high-concentration impurity diffusion layer 24 is shaped. A source region 25 is formed to the layer 24, and the surface is coated with a silicon oxide film 26. |
