| 摘要 |
PURPOSE:To form a groove on the surface of substrate, partly remove the surface of groove, prevent change of impurity concentration at the groove interface and prevent generation of crystal defect by removing an oxide which has been formed by selective oxidation on the substrate surface. CONSTITUTION:After forming an N type buried region 2 to the required area of P type silicon substrate 1, an N type layer 3 is caused to grow in the specified thickess. A nitride film 4 is deposited in the specified thickness to the surface of layer 3 as the oxidation proof film and it is then removed selectively only from the area where a groove is to be formed. Then, a silicon dioxide film 5 which extends up to the substrate 1 is formed by pressurized oxidation and the element regions 11, 12 are virtually separated. The silicon 5 is removed by dipping the structure into the SiO2 etchant and the region 13 of groove is converted to a nitride film 14. The high concentration region (N type channel) 6 is removed, the regions 11, 12 are separated electrically, and the film 4 is removed. Thereafter, an oxide film 7 is deposited, the groove is buried with a polycrystalline silicon 8, an oxide film 9 is deposited thereon and thereby generation of crystal defect can be prevented. |
