Method for forming a v-shaped floating gate

摘要

The invention provides a floating gate memory cell, where the floating gate comprises a first lateral end region and a second lateral end region. A middle region is positioned towards a middle of the floating gate with respect to the first lateral end region and the second lateral end region. The thickness of the floating gate decreases continuously from at least one of the first or second lateral end regions to the middle region. This invention also provides for a method of forming a contoured floating gate for use in a floating gate memory cell. The method includes forming a polysilicon structure between a first alignment structure and a second alignment structure, where the polysilicon structure has a maximum thickness at a first lateral end region adjacent to the first alignment structure and at a second lateral end region adjacent to the second alignment structure, and where the polysilicon structure has a minimum thickness at a middle region positioned between the first lateral end regions and the second lateral end region. The method further includes forming a polysilicon layer over the polysilicon structure such that the polysilicon layer adopts a contour of the polysilicon structure.