| 摘要 |
PURPOSE:To prevent the breakage of a film by a method wherein a silicon hydroxide film containing impurities and a solvent is applied on a substrate through a mask with a predetermined pattern and the opening section of the mask is formed in taper shape when the impurities are diffused in the substrate by applying heat treatment. CONSTITUTION:An SiO2 film 2 serving as a diffusion mask is formed on a P type Si semiconductor substrate 1 and etched halfway by using a resist film 13 as a mask. Then, with the film 13 slightly ashed by using plasma-asher, the opening section of the film 13 is expanded. At that time, etching is again performed. After forming an opening pattern with a taper shaped section on the film 2, the substance dissolved Si(OH)4 and As2O3 including an N type impurity in acetone is applied to the surface to form a layer 3. Next, heat treatment is applied to make an N type region 5 by diffusing N type impurity As into the substrate 1. Therefore, a tapered edge 7 exists. Thus, the film 3 will not be broken even if the film 3 contracts at the time of heat treatment. |
