Patent ID: 6046085
Filing Date: 2000-04-04
Classification: H01L

Abstract:
A method of preventing poly stringers in the formation of a memory device, comprising the steps of:forming at least one field oxide region in a substrate;forming a tunnel oxide over the substrate;forming a first polysilicon layer over the tunnel oxide;forming a poly mask having a mask profile over the first polysilicon layer;etching the first polysilicon layer in portions exposed by the poly mask, thereby creating a first polysilicon layer etch profile, wherein the first polysilicon layer etch profile is substantially ideally anisotropic and independent of the mask profile;forming an insulating layer over the etched first polysilicon layer and a conductive layer over the insulating layer;etching portions of the conductive layer, thereby forming at least one word line;etching the insulating layer in regions adjacent the at least one word line, thereby leaving a substantially vertical insulative fence along the first polysilicon layer etch profile; andetching the first polysilicon layer in regions adjacent the at least one word line, wherein the etching of the first polysilicon layer is substantially anisotropic and removes substantially all the polysilicon in regions adjacent the at least one word line, resulting in the prevention of poly stringers.