METHOD FOR FABRICATING SEMICONDUCTOR NANOCRYSTAL AND SEMICONDUCTOR MEMORY DEVICE USING THE SEMICONDUCTOR NANOCRYSTAL

摘要

PROBLEM TO BE SOLVED: To provide a method for fabricating semiconductor nanocrystal having a good controllability of concentration and size and a small variation property; and a semiconductor nonvolatile memory device using the semiconductor nanocrystal, in which thickness of an insulating film between the nanocrystal and a channel region is easily controlled, variation in characteristics such as threshold and writing performance is small, and capable of fast rewriting.;SOLUTION: An amorphous silicon thin film 3 is deposited at a low pressure of the atmospheric pressure or below on a tunnel insulating film 2 formed on a silicon substrate 1. After the amorphous silicon thin film 3 is deposited, the thin film 3 is subjected to heat treatment at a temperature of the depositing temperature of the thin film 3 or more in non-oxidizing He gas atmosphere. A plurality of spherical nanocrystals 4 having a diameter of 18 nm or less are formed on the tunnel insulating film 2 at intervals with each together. The plurality of nanocrystals 4 are used as floating gates of a semiconductor memory device.;COPYRIGHT: (C)2004,JPO