| 摘要 |
PROBLEM TO BE SOLVED: To prevent an occurrence of voids in trenches to improve yield.SOLUTION: A semiconductor device manufacturing method comprises: forming a mask pattern including a first nitride film in a predetermined region on a surface of a substrate; forming trenches on the substrate by etching the substrate by using the mask pattern as a mask; forming a first thermal oxide film in the trenches and on an exposed surface of the first nitride film; forming second nitride film on the first thermal oxide film so as to fill the trenches; performing etchback on the second nitride film so as to make the second nitride film remain on a part of the trenches; forming a second thermal oxide film on the remaining second nitride film and on an exposed surface of the first thermal oxide film; forming a buried oxide film on the second thermal oxide film so as to fill the trenches; removing a part of each of the buried oxide film, the second thermal oxide film and the first thermal oxide film by grinding by using the first nitride film as a stopper; etching a remaining part of the buried oxide film so as to align a surface position of the remaining buried oxide film with a surface position of the substrate; and subsequently removing the first nitride film. |
