METHOD OF MANUFACTURING SEMICONDUCTOR DEVICE

• Main Authors: UCHIMURA Katsuhiro, HORIE Kazuya, TOI Kazuhiro, NAKANO Masakazu
• Format: Patent
• Language: English
• Published: 08.03.2018
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; SEMICONDUCTOR DEVICES

To achieve the above, poly-silicon films are formed inside a trench in a main surface of a semiconductor substrate and over the semiconductor substrate. Further, phosphorus is thermally diffused into each poly-silicon film from a phosphorous film over an upper surface of the poly-silicon film. Still further, a silicon oxide film formed in a surface layer of the poly-silicon film by the thermal diffusion process is removed by a first dry etching process using a fluorocarbon gas or a hydroxy-fluorocarbon gas. Then, by performing a second dry etching process using a Cl2 gas etc., an insulating film is exposed and, thereby, a trench gate electrode including the poly-silicon film is formed.