| 摘要 |
PURPOSE:To obtain an insulating gate type electric field effect transistor in which a pattern accuracy is sharply improved and a leak characteristics is also improved by selectively etching a boron phosphate silicon glass film and a silicon oxide film and by forming an insulating film through oxidizing the exposed surface of a semiconductor layer. CONSTITUTION:A P<+> type semiconductor layer 105, a silicon oxide film 102 and a boron phosphate silicate glass film (BPSG film) 106 are formed on a main surface of a P-type semiconductor substrate 101. The BPSG film 106 and the silicon oxide film 102 are etched using a photoresist film 104 as a mask with the anisotropy etching method. After an exposed surface of the P<+> type semiconductor layer 105 is changed into a silicon oxide film by being exposed in an oxidizing atmosphere, a gate insulating film 111 is formed. The BPSG film 106 reflows, and a square shape of opening portion end changes into a round shape and also a dimension accuracy is not spoiled. After this, a conventional manufacturing process of a silicon gate MOS type semiconductor device is done. |
