| 摘要 |
PURPOSE:To render the formation of a contact simple by a method wherein a polycrystalline film and a doped silica film are selectively formed at an opening provided at an N-type diffusion region and a P-type diffusion region and impurity, contained in the doped oxide layers, is used for the diffusion. CONSTITUTION:An N-type well 2, a field insulating film 3, a P-type diffusion region 4, and an N-type diffusion region 5 are formed on a P-type semiconductor substrate 1, thereafter an interlaminar insulating film 6 is built thereon, and a contact opening is provided at the insulating film 6 over the diffusion layers 4 and 5. Next, a polycrystalline silicon film 7 is formed on the surface including the opening, an N-type doped silica film is rotationally applied so as to form a photoresist film 9 selectively thereon. The photoresist 9 is removed after the film 8 is removed through etching and then a P-type doped silica film 10 is formed through application. Next, calcination is performed at low temperature for the formation of an N-type and a P-type doped oxide layers 11 and 12 and heat treatment is performed to diffuse impurity doped in both the oxide layers 11 and 12 to form the contact of the polycrystalline silicon film 7 with the N-type and the P-type diffusion layers 5 and 4. By these processes, the formation of a contact is simplified.
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