| 摘要 |
PURPOSE:To obtain a groove type capacitor in which a software error hardly occurs by forming a groove, then burying the groove with high impurity density polycrystalline silicon, and providing the step of forming a new groove. CONSTITUTION:When a groove 2 is formed in a substrate 1, a groove which is larger than a groove to be eventually desired to be obtained, and the groove is subsequently buried with polycrystalline silicon 3 containing boron in high density except the center. After a resin 4 is coated, it is flattened by etching, the resist is further removed to form the groove 2 coated with P<+> type polycrystalline silicon. Then, a trench is buried with phosphorus glass 5, and thermally diffused to form an N<-> type diffused layer 6 on the region of the surface of the trench. After the glass 5 is removed by etching with ammonium fluoride, an oxide film 7 and an electrode 8 made of P<+> type polycrystalline silicon are formed. |
