| 摘要 |
PURPOSE:To eliminate the occurrence of a crystal defect called an Sb rosette which is produced during a diffusion process of Sb, by a method wherein, in a process to manufacture a semiconductor device which uses an Sb silica film while the Sb is diffused selectively by making use of an SiO2 film as a mask, the Sb silica film is coated in such a way that its film thickness is less than a prescribed thickness. CONSTITUTION:An SiO2 film 42 is grown to be 1 mum in thickness on a P-type silicon substrate 41; a window 43 is opened in a desired position of the SiO2 film 42 by using a photolithographic technique. Then, an Sb silica film 44 is spin-coated on a whole area of the SiO2 film 42 including the window 43 in such a way that its film thickness is less than 500 Angstrom . After that, the assembly is baked in the air at 200 deg.C for about 10 min so that a residual solvent in the Sb silica film is evaporated. Then, if the assembly is heat-treated at 1200 deg.C in an active gas atmosphere whose 5 % is composed of oxygen, an Sb diffusion layer 45 is formed inside the silicon substrate 41. By this setup, an Sb rosette is not produced inside the SiO2 film 42.
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