| 摘要 |
PURPOSE:To control the depth of diffusion and thereby to obtain a shallow diffused layer by a method wherein first an insulating film is connected on the surface of a semiconductor layer, an opening is made in the film, a polycrystalline Si layer is provided only on the wall surface of the opening, a high-melting metal film is connected inside the opening, and impurity ions are implanted through this film. CONSTITUTION:An SiO2 film 2 is connected on a P type Si substrate 1, an opening 3 is made so that it corresponds to a diffused layer to be formed, and a polycrystalline Si layer 9a is formed only on the side wall surface of the opening. Next, a film 10 is connected on said side wall, the exposed bottom surface of the opening 3, and further the edge portion of the film 2, and N type impurity ions are implanted in the whole area containing this film 2. Thereafter a heat treatment of 1,000 deg.C and about 20min duration is applied, so as to obtain a shallow N type diffused layer 4 in the substrate 1 under the opening 3 and also to form a thin W silicide layer 11 on the film 10. Afterward, an Al wiring 7 is connected, extending from the top of the layer 11 onto the film 2. According to this method, Al spiking does not occur on the surface of the layer 4, and the depth of the layer 4 is lessened. |
