| 摘要 |
PURPOSE:To make protectability against contamination from the outside stronger and improve moisture resistant property by a method wherein the thermal treatment is applied to high density phosphorus silicate glass film as passivation film in the high density and wet oxygen atmosphere. CONSTITUTION:An aperture is made in thermal oxide film 4 by photoetching and PSG (phosphorus silicate glass) film 5 is formed. The wafer 1 is inerted into a diffusion oven of 700-900 deg.C. Mixed gas atmosphere of O2:0.2l/min and N2: 1.8l/min. is introduced into this oven. After the wafer 1 is inserted, the wafer is slowly heated by increasing the oven temperature at the rate of 5 deg.C/min. After the oven temperature is balanced and kept at 1,050 deg.C for approximately 30min, the wafer is slowly cooled by decreasing the oven temperature at the rate of 3 deg.C/min. When this slow cooling is started, the atmosphere is replaced by the wet oxygen atmosphere and at the intermediate of the slow cooling the atmosphere is again replaced by the dry nitrogen atmosphere. With this constitution on N<+> type emitter region 6 is formed and simultaneously a thermal oxide film 7 is formed between the region 6 and the film 5. |
