| 摘要 |
PURPOSE:To attenuate the junction leak current when a buried type element isolation technique is used by a method wherein an inversion preventing layer is provided in such a manner that one of the side walls, opposing each other through the intermediary of the element isolation material located inside a groove, makes a vertical surface to the main surface of a substrate and the other side wall makes a plane direction (111) to the vertical surface. CONSTITUTION:An inclined surface of plane direction (111) is formed in the vicinity of the main surface of a substrate 21 by performing a directional chemical etching such as KOH and the like using a silicon nitride film 23 as a mask. Then, residual CVD oxide films 24' and 24' are formed by performing an etching, and after a P-channel element region side has been removed by performing a selective etching, a well isolation proove 27 is formed on the substrate 21 by performing an anisotropic etching. Then, after the residual CVD oxide film 24' has been removed by performing an etching, a boron-doped layer 29 is formed on the bottom face in the groove 27 and on the inclined surface of the plane direction (111), a CVD oxide film 30 is buried in the internal part of the groove 27, a heat treatment is performed, the boron-doped layer 29 is activated, and a P<-> type inversion preventing film 31 is formed. |
