| 摘要 |
PURPOSE:To improve the reliability of a semiconductor element by forming a base connecting opening by a reactive sputtering etching process, etching a PSG layer on a SiO2 film without fault and retaining the PSG layer on the side surface of an emitter connecting opening. CONSTITUTION:A p-type base 2 is formed on an n-type silicon 1, an opening 4 is perforated at a SiO2 film 3, P is diffused to form an n-type layer 5 thereon. In this case PSG layers 6, 7 are formed on the surface of the film 3. A resist mask 8 is then coated thereon, the PSG layer 6 and the film 3 are selectively etched by a reactive sputtering etching process, and opening 9 is perforated thereat. The resist 8 is then removed, the thin PSG on the emitter layer surface is removed by a dilute fluoric acid, and emitter and base electrodes 10 and 11 are formed thereon. According to this process, no fault is produced even if the layer 6 is placed on the film 3, the PSG film 7 is retained at the side surface of the emitter electrode opening, and the distance between the surface of the opening and the emitter and the base junction become substantially long so as to prevent leakage current and shorting accident. |
