| 摘要 |
PURPOSE:To obtain a P layer by Ga diffusion easily onto a Si substrate by stacking a SiO2 film and a Si3N4 film onto the Si substrate, selectively implanting Ga ions into the SiO2 film and thermally treating the surface in an inactive atmosphere. CONSTITUTION:The SiO2 film 2 (0.1-0.2mum thickness) in which the diffusion velocity of Ga is large and the Si3N4 film 3 (0.01-0.02mum thickness) in which the diffusion velocity of Ga is small are stacked onto the N type Si substrate 1, Ga ions 5 are implanted into the film 2 by energy in approximately 30-80keV, and a Ga ion layer 6 is formed into the film 2. When Ga is thermally diffused within the range of 1,100-1,250 deg.C, the Si3N4 film 3 functions as an outward diffusion preventive mask for Ga, even Ga having low vapor pressure is easily diffused in high concentration without generating detects and strains in the Si substrate 1, and the P layer 8 can be formed. |
