Method of forming SI tip by single etching process and its application for forming floating gate

摘要

The invention provides a method of forming a silicon tip by a single etching process, as well as a method of forming a tip floating gate to increase erase speed. Etching gases comprising (1) chlorine and/or (2) oxygen/helium are performed to form a silicon tip without bottom dimple. The invention may further control the tip angle by adjusting the etching parameters of gas compositions and ratios, chamber pressures, and radio frequency powers.