Substrate for semiconductor integrated circuit

Abstract

Abstract PURPOSE:To improve the yield of a substrate for a semiconductor integrated circuit of insulating and isolating structure with polysilicon as a support by forming a polysilicon layer of modified crystalline configuration, and forming a film or region for preventing the invasion of oxygen to the surface, thereby preventing the curvature in the manufacturing step. CONSTITUTION:An isolating groove 12 is formed on an Si substrate 11, and a thermally oxidized film 13 is formed on the surface. Then, a polysilicon layer 14 is formed on the film 13 by a CVD device in a mixture atmosphere of halogenated silane reaction gas and impurity gas, an SiO2 filn 15 is accumulated in the same device, and a polysilicon layer 16 is further formed under the same conditions as the layer 14. The layer 16 is so polished as not to expose the layer 15 to be flattened, and is polished and removed until the Si single crystal 11 side reaches the isolating groove 12, a single crystalline layer 17 is retained insularly as an IC substrate 18. In this manner, it can prevent the bending of the substrate 18 at the time of accumulating polysilicon, oxidizing and diffusing it in the step of manufacturing the element, and the yield of the fine machining, e.g., photographic step can be improved.

Inventors

• 👤 Takaya Suzuki
• 👤 Akio Mimura

Bibliographic Details