Patent ID: 7205245
Filing Date: 2007-04-17
Classification: C09K,H01L

Abstract:
1. A method of forming trench isolation within a semiconductor substrate, comprising: forming a silicon nitride-comprising layer over a semiconductor substrate; etching a series of isolation trenches within the semiconductor substrate using a portion of the silicon nitride-comprising layer as a mask; after etching the isolation trenches, depositing an aluminum oxide-comprising layer over tops and sidewalls of the silicon nitride-comprising mask and to within the isolation trenches to less than fill the isolation trenches; after depositing the aluminum oxide-comprising layer, filling remaining volume of the trenches with isolation material; after the filling, removing the isolation material effective to expose the silicon nitride-comprising mask; and after the exposing, etching the silicon nitride-comprising mask with an etching solution comprising HF and an organic HF solvent under conditions effective to etch the silicon nitride-comprising mask substantially selectively relative to the aluminum oxide-comprising layer and relative to the isolation material.