SEMICONDUCTOR DEVICE AND MANUFACTURING METHOD THEREFOR

摘要

PURPOSE: A semiconductor device and a method for manufacturing the same are provided to improve reliability of the device by securing a sufficient channel length in a limited area. CONSTITUTION: A semiconductor devide includes an oxide film(22) on a semiconductor substrate(21) of a concave-convex shape. The first polysilicon layer(23) as a planarization layer is formed on the oxide film(22). A field oxide film(24) is formed in a field region of the first polysilicon layer(23). A gate oxide film(25) and a gate electrode(26a) are formed in the active region. A source/drain impurity diffusion region(28) is formed within the surface of the first polysilicon layer(23) at both sides of the gate electrode(26a).