Patent ID: 6297110
Filing Date: 2001-10-02
Classification: H01L

Abstract:
A method of forming a contact opening, comprising the steps of:forming a first conductive structure in a substrate adjacent a field oxide region;forming a dielectric layer over the first conductive structure;forming a film having a high etch selectivity to the dielectric layer for a given etchant;patterning and etching the film to form a stack at least partially over the first conductive structure;forming an insulation layer over the dielectric layer and stack wherein the stack has a high etch selectivity to the insulation layer for a given etchant;etching the insulation layer to expose an upper surface of the stack;etching the stack to form an opening in the insulation layer exposing the dielectric layer in the opening;etching the exposed dielectric layer in the opening exposing the underlying first conductive structure;forming a conformal polysilicon layer over the insulation layer and in a portion of the opening overlying the first conductive structure;doping the conformal polysilicon layer, wherein doping the conformal polysilicon layer further dopes a region underlying the conformal polysilicon layer in the substrate and adjacent the field oxide region; andforming a conductor over the conformal polysilicon layer.