| 摘要 |
PURPOSE:To obtain an Si gate type FET in high reliability by a method wherein after an active region is formed in a semiconductor by injecting ions through an oxidized film, the film oxide contaminated by the ions is removed and the region is covered with a new insulating film. CONSTITUTION:A thick field insulating film 3 is formed on the periphery of a P type Si substrate 1, a thin gate insulating film is provided on the surface of the substrate 1 surrounded by the film 3 and in the center of the insulating film, a gate electrode 4 made of the polycrystal Si is fitted. Then, with this as a mask, N type impurity ions of As and the like are driven in through the gate insulating film to form N type drain regions 2, 2', and the surface is applied an etching until the gate insulating film is disappeared to remove the ion contaminated layer. After then, film oxide 3' containing PSG is newly attached to protect the surface and at this time, the content of PSG is prescribed for 3-9mol% and a P type impurity diffusion depth 20 in PSG which is reached when the film 3' is attached is made shallower than those of the regions 2 and 2'. |
