| 摘要 |
PURPOSE:To form a single crystal Si epitaxially only at an aperture and obtain a substrate of flatness with less crystal defect by single crystallizing also the thin film on a side wall by a method wherein an SiO2 on a single crystal Si substrate is opened, and a polycrystalline or amorphous Si of prescribed conductivity type is formed only on the side wall. CONSTITUTION:A thermal oxide film on the surface {100} of an Si substrate is reactively ion-etched, thus forming a pattern 12 having a vertical wall by leaving an oxide film of approx. 500Angstrom . Poly Si 13 of prescribed conductivity type is deposited by a CVD method and reactively ion-etched, and accordingly the poly Si 13 is left only on the side surface of the oxide film 12. Next, the oxide film 12 is etched with dilluted HF solution, and single crystal Si 15 is selectively grown on the suface 14 of the exposed substrate by a vapor phase epitaxial method. At this time, the poly Si on the wall surface is also single-crystallized into an integral body with the Si 15, thus generating no facets or unnevenness in the neighborhood of an oxide film interface, and therefore a flat epitaxial surface can be obtained. Deciding the wall surface material as amorphous Si is likewise effective. |
