| 摘要 |
PURPOSE:To reduce lattice defects by a method wherein a porous silicon oxide layer is provided with a Y-shaped cross section. CONSTITUTION:On the surface of a P-type single-crystal silicon substrate 20, an N-type epitaxial layer 21 and mask 23 are formed. Next, the substrate 20 is subjected to etching for the formation of a V-shaped groove. A process follows wherein boron is deposited for the formation of a layer 24 containing a P-type impurity within the epitaxial layer 21, when the layer 24 is provided with a Y-shaped cross section. Anodic treatment is accomplished for the conversion of the layer 24 into a porous silicon layer 26. Next, oxidation is accomplished in an oxygen atmosphere for the development of the porous silicon layer 26 into a silicon dioxide layer 22. The silicon dioxide layer 22 is larger in volume than the porous silicon layer 26, as the result of which the V-shaped groove is filled with silicon dioxide. |
