Semiconductor memory and method for fabricating the same

Claim 1

A semiconductor memory which is formed in a semiconductor substrate comprising: capacitors (1) for storing information; insulated-gate field effect transistors (2) for reading out the signal charges stored in said capcitors; word lines (41, 42) for applying signals to a gate electrode (4) of the insulated-gate field effect transistors; and data lines (3, 31, 32) for reading out the information stored in said capacitors (1); wherein the capacitors (1) each include electrodes (24) formed at the side walls of one of a plurality of recesses provided in the semiconductor substrate, wherein the side walls of each of the recesses are covered by an insulating layer and a layer of conductive material is formed over said insulating layer to form a capacitor plate (82) separated from said side walls of the recesses by said insulating layer, wherein a source or drain of each of said insulated-gate field effect transistors is respectively connected to one of said electrodes (24, 82) of the recess, wherein a drain or source of each of said insulated-gate field effect transistors is connected to one of said data lines, wherein the gate electrode of each of said insulated-gate field effect transistors is connected to one of said word lines, characterized in that the insulating layer has at least a first insulating film (18) and a second insulating film (19).

Claim 5

A method for fabricating a semiconductor memory of any of the claims 1 to 3,characterized by the steps of: a) forming an insulation film (11, 111) on a semiconductor substrate (10); b) forming a groove (17) at a selected area of said semiconductor substrate (10) through said insulation film (11, 111); c) depositing an insulation film (18, 19) and a conductive film (8) in stack on the surface of said groove (17).