| 摘要 |
PURPOSE:To make high speed actuation feasible while improving the reliability by a method wherein, after covering a gate polysilicon with a thin insulating film, said film is coated with a silicate glass containing the first conductive type impurity and then a silicon nitride film while the main surface of silicon semiconductor substrate is ion-implanted with the second conductive type impurity. CONSTITUTION:A P-type conductive layer (P-well) 2 and an N-type conductive layer (N-well) 3 are formed in respectively different regions on one main surface of a silicon semiconductor substrate 1 by means of implanting boron or phospho rus for long time drive-in within N2 atmosphere. A polysilicon layer 6 is dryetched utilizing a photoresist layer 7 as a mask firstly for thermal oxidation of gate polysilicons 8, 9 to form polysilicon oxide films 10. Secondly overall surface is coated with high concentration phosphorus silicate glass 20 by means of spin-coating process or atmospheric CVD process further growing a silicon nitride film Si3N4 12. Finally the silicon nitride film 12 may be removed by one sheet type dry-etching mainly comprising CF4 utilizing a photoresist layer 13 as a mask. |
