| 摘要 |
PURPOSE:To allow the area a memory cell occupies to be reduced for higher integration by a method wherein the memory cell is constructed in the direction of the depth of a semiconductor substrate. CONSTITUTION:In a trench 23 constructed in the direction of the depth of a semiconductor substrate 21, a conductive material is formed to serve as a floating gate 25, so buried as to be isolated from its neighboring regions by an insulating film 27. A first high-concentration region, to serve as a control gate 29, is formed on one of the walls of the trench 23 and faces said conductive material. A second high concentration region to serve as a drain region 31 is formed on the surface of the semiconductor substrate 21 on the side of the other side wall of the trench 23. Further, beneath the second high-concentration region and on the side wall of the trench 23, a third high-concentration region is formed to serve as a source region 37. The result is a memory cell occupying but a reduced area, which will lead to higher integration and improved device characteristics.
|
