| 摘要 |
PURPOSE:To increase the withstand voltage of an element by forming a P-Si- glass layer of 3-4mum thick on the surface of a semiconductor substrate, thereby reducing the capacity between the substrate and electrodes, wiring layer and an electric field. CONSTITUTION:A P-Si-glass PSG layer 13' is formed, for example, 1.5mum of thickness by gas reaction of SiH4, PH3 and O2 on an SiO2 film 12. A P-Si-glass PSG layer 13' is formed, for example, in a thickness of 1.5mum by vapor phase reaction of SiH4, PH3 and O2 on an SiO2 film 12. Then, the layer 13' is densified by heat treatment of the temperature such as 700-950 deg.C to be glassy. Further, a PSG layer 13'' having the same thickness as the layer 13' is formed on the layer 13', and is similarly heat treated. Subsequently, these steps are repeated to obtain a PSG layer 13. The PSG layer 13 of approx. 3-4mum can be obtained by this steps. |
