Patent ID: 6027985
Filing Date: 2000-02-22
Classification: H01L

Abstract:
A method for forming an element isolating film of a semiconductor device, comprising:providing a semiconductor substrate;sequentially forming a pad oxide film and a first nitride film over the semiconductor substrate;over-etching the first nitride film and the pad oxide film using an element-isolating mask, thereby forming a first hole in the semiconductor substrate;cleaning the entire upper surface of the resulting structure using an etch solution;forming second nitride film spacers on side walls of the selectively etched first nitride film and pad oxide film and the first hole;etching an exposed portion of the semiconductor substrate using the first nitride film and the second nitride film spacers as a mask so as to form a second hole in the first hole of the semiconductor substrate;removing an etch residue left in the second hole after the formation of the second hole;thermally oxidizing a surface of the second hole, thereby forming a thermal oxide film; andremoving the first nitride film, the pad oxide film and the second nitride film spacers, thereby forming the element isolating film.