Self-aligned in-laid split gate memory and method of making

摘要

A method includes forming a silicon nitride layer and patterning it to form a first opening and a second opening separated by a first portion of silicon nitride. Gate material is deposited in the first and second openings to form first and second select gate structures in the first and second openings. Second and third portions of silicon nitride layer are removed adjacent to the first and second gate structures, respectively. A charge storage layer is formed over the semiconductor device after removing the second and third portions. First and second sidewall spacers of gate material are formed on the charge storage layer and adjacent to the first and second gate structures. The charge storage layer is etched using the first and second sidewall spacers as masks. The first portion is removed. A drain region is formed in the semiconductor layer between the first and second gate structures.