| 摘要 |
PURPOSE:To prevent the breakage of a wiring layer and short circuit at crossing portions between the multi-layers by softening and fluidifying the upper layer of an interlayer insulating film at the temperature lower than that of the lower layer, forming said layer at a faster etching speed, and smoothing the surface of the element. CONSTITUTION:A lower layer 8 comprising CVD SiO2 film (PSG) containing phosphorus of low-concentration, e.g., 0-3wt%, is formed on the surface of an element. Then, an upper layer 9 comprising CVD SiO2 film (PSG) containing phosphorus of 8-12wt% is formed. The upper layer 9 is softened by heat treatment and fluidified, thereby a covering state with a gentle slope can be obtained. |
