Formation of silicon quantum dot for semiconductor memory device, involves applying isotropic etching to substrate using barrier film as mask, and oxidizing isotropic etched substrate with thermal treatment to form gate oxide film

摘要

A silicon quantum dot is formed for a semiconductor memory device, by applying an isotropic etching to a substrate using a barrier film as a mask, and oxidizing the isotropic etched substrate with thermal treatment to form a gate oxide film. Formation of a silicon quantum dot (145) for a semiconductor memory device, comprises forming a pad oxide film and a sacrificial insulation film on a silicon substrate (100). A wall layer is formed by etching the sacrificial insulation film. A spacer is formed at the sidewall of the wall layer. A silicon pattern is formed by etching the silicon substrate as much as a predetermined thickness using the spacer as a mask. A barrier film is formed for burying the upper surface and the side surface of the silicon pattern. An isotropic etching is applied to the substrate using the barrier film as a mask. The isotropic etched substrate is oxidized with thermal treatment to form a gate oxide film (160).