| 摘要 |
PURPOSE:To improve the integration of semiconductor memory as well as the operating margin of memory cell and the alpha ray resisting strength by a method wherein an insulating film formed inside grooves on the main surface of semiconductor substrate and then filled with conductor is utilized as a speed up condenser. CONSTITUTION:U type grooves 4a, 4b are formed penetrating through an N<+> type buried layer 2 selectively formed on a P type silicon semiconductor substrate 1 and an N<-> type epitaxial layer 3 vapor-grown on the N<+> type buried layer 2. Then a relatively thin insulating film 5 such as an oxide silicon film is formed inside the U shaped grooves 4a, 4b by means of thermal oxidation etc. while the inside of insulating film 5 is filled with conductor 6 such as polysilicon containing impurity. In such a constitution, the capacity between conductor 6 and semiconductor substrate 1 may be actively utilized as condenser C1. |
