JPS5519820A - Semiconductor device - Google Patents

Abstract

PURPOSE:To obtain a small-type dynamic RAM by minimizing its area occupied by a memory cell section and increasing its information-storing capacity. CONSTITUTION:A P-type Si 101 is provided with a thick film 102 of SiO2; a transistor forming a cell section makes a gate oxide film 103; an injection of ion provides an N<+> gate electrode layer 104; and using impurity-adding multi-crystal or non-fixed type Si layers 105 and 106 as a source and a drain, a section adjoining a gate oxide film of a layer 107 is turned into a channel. A cell's information- accumulating capacity is composed by surface of the Si base and a layer 106 through an SiO2 layer 108. And then, this is covered with an SiO2 layer 109. The source 105 on a thick oxide film 102 is connected to a bit wire, a gate electrode 104 and a word wire so that information can be accumulated on a part of surface of the layer 106 adjoining the thin layer 108. Since parastic capacity is reduced in this mechanism, it is possible to reduce an area of information-accumulating capacity in proportion to reduction in the parastic capacity, the information-accumulating capacity can be doubled by piling the capacity section in a layer.