| 摘要 |
PURPOSE:To enable the diffusion in good reproducibility by a method wherein P2O3 is removed in a good efficiency by heat treatment when P is diffused in an Si substrate. CONSTITUTION:When an N type Si substrate is diffused with P to form an N<+> layer, a PSG film composed of SiO2+P2O5 is formed on the surface. The P2O5 in the PSG film is diffused outwardly by the subsequent diffusion treatment, contaminates the atmosphere and impractices the good reproducible diffusion of impurities. Thereupon, the P2O5 only runs out by applying the treatment for about two hours under the conditions of 900-1,100 deg.C, 1X10<-2> torr after being formed, and the SiO2 not containing P2O5 is left on the Si surface. Thereafter, the impurities can be diffused in good reproducibility. |
