| 摘要 |
PURPOSE:To form an island of dielectric isolation structure by etching a polycrystalline silicon layer through alkali etching in a self-alignment manner as an etching mask for isolating a single crystal silicon layer by an insular isolating groove by a silicon oxide film on the single crystal silicon layer. CONSTITUTION:Silicon oxide films 41 are formed on the upper surfaces of epitaxial growth layers 38 through oxidation heat treatment, and polycrystalline silicon layers 40 are polished from the upper surface sides. The adhering silicon oxide films 41 are also removed simultaneously at that time, one parts of the polycrystalline silicon layers 40 are exposed, and the silicon oxide films 41 remain only on the upper surfaces of single crystal silicon layers 39 and the side surfaces of the polycrystalline silicon layers 40. The polycrystalline silicon layers 40 are etched and treated by using an alkaline liquid such as an alkali mixed liquid of KOH, alcohol and water, and complementary type islands isolated by grooves 43 are formed. One parts of the side surfaces of the single crystal islands 39 are etched at that time, but newly exposed 111 faces display stopping action to subsequent etching because of alkaline anisotropic etching, and the single crystal islands 39 are formed in a self-alignment manner without getting out of their shapes. |
