Method of ashing a photoresist

摘要

A method is provided for stripping a photoresist with a carbonized crust formed during a high dose ion implant. The method may be performed in any etch tool or asher including those where a plasma is generated with a RF discharge source and bias power and tools with a microwave downstream plasma flow. An ICP plasma source is preferred for generating plasma from a flow of oxygen and one or more CxHyFz gases such as CH3F and CH2F2 where x, y and z are >=1. A high photoresist removal rate of from 0.2 to 2 microns per minute is achieved while reducing thickness loss in exposed oxide, polysilicon, and silicon layers compared with conventional methods that employ O2 and CMFN gases. For NMOS and PMOS transistors, Idsat and contact junction leakage are improved.