Abstract: An isolator for isolating semiconductor devices, components of an integrated circuit, on a semiconductor substrate, wherein the isolator is delimited by walls of a trench formed on a top surface of the semiconductor substrate, and the trench is filled with a silicon oxide layer deposited by a chemical vapor deposition method. A small ditch created in the middle of a top surface of the silicon oxide layer in the trench is filled with silicon, and at least a top surface of the silicon is thermally oxidized to form another silicon oxide layer.

Abstract: A semiconductor memory having a plurality of memory cells each including a single capacitor and a single transistor for storing one bit are formed on a semiconductor substrate. Each terminal of the respective transistors of the memory cells are commonly connected to a common wiring portion, and the capacitor of each memory cell is disposed in a trench which is formed by forming a groove-like shape along the outer periphery of the semiconductor substrate for one or two adjacent transistors. The capacitor includes a first insulating film disposed over the inner wall surface of the trench, a first electrode formed entirely or partially on the surface of the first insulating film for being supplied with a predetermined voltage, a second insulating film disposed entirely over the surface of the first electrode, and a second electrode disposed on the second insulating film in an area corresponding to the inner sidewall surface of the trench and connected to the other terminal of the transistor.