| 摘要 |
PURPOSE:To alleviate damages of a shallow contact part due to etching, by performing etching of an upper insulating film under the conditions so that the etching rate is larger than that when a lower insulating film is etched. CONSTITUTION:On the surface of a semiconductor substrate 1, a first region 4 and a second region 3, which is lower than the first region 4, are formed. A first insulating film 10 is formed on the first and second regions 4 and 3 including said surface. A second insulating film 11, whose surface is flat, is formed on the film 10. Holes reaching the first insulating film 10 are formed from the position of the second insulating film 11 corresponding to the first and second regions 4 and 3 by the first etching. The etching is performed under the condition so that the etching rate is larger than that when the first insulating film 10 is etched. Then, holes reaching the first and second regions 4 and 3 are formed from the positions of the surface of the second insulating film 11 corresponding to the first and second regions 4 and 3 by the second etching. At this time, a PSG film is used as the first insulating film 10, and a BPSG film is used as the second insulating film 11. The etching rate is controlled by the etching method and the quality of the insulating films 10 and 11.
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