Patent ID: 6924196
Filing Date: 2005-08-02
Classification: H01L

Abstract:
1. A process for fabricating a semiconductor device comprising the steps of: providing a semiconductor substrate; forming a silicon nitride layer overlying the substrate; deposition a layer of polycrystalline silicon overlying the silicon nitride layer; forming an anti-reflective coating overlying the layer of polycrystalline silicon, the anti-reflective coating comprising a first layer of oxide and a second layer of silicon oxynitride overlying the first layer; pattern etching the anti-reflective coating, the layer of polycrystalline silicon and the silicon nitride layer to form a stack, the stack having an edge and a top; removing the remaining layer of silicon oxynitride in the stack by etching in hot phosphoric acid before subjecting the layer of silicon oxynitride to any temperature greater than about 400° C.; oxidizing the layer of polycrystalline silicon in the stack after the step of removing the remaining layer of silicon oxynitride in the stack.