| 摘要 |
PURPOSE:To obtain a uniform structure without structually sparse regions and an approximately flat surface after etching in polycrystalline silicon filling an insulating and isolating groove on a silicon substrate, by heat treating the polycrystalline silicon at a specific temperature. CONSTITUTION:A groove 5 formed on the surface of a silicon substrate 1 is covered with an insulation film 2 and polycrystalline silicon is caused to grow in the groove. The polycrystalline silicon is then heat treated at a temperature between about 900 deg.C to 1,100 deg.C, preferebly at about 1,000 deg.C, in the presence of nitride. The polycrystalline silicon 13 thus heat treated is etched to form an insulating and isolating region whose upper surface is approximately flat and in continuation with the surface of the aperture of the groove 5. Since the polycrystalline silicon is kept in a uniform state by the high temperature heat treatment, no deep concave is produced at the center of the groove during the etching process. |
