PLASMA ETCHING TREATMENT THAT USES POLYMER ETCHING GASES OF DIFFERENT ETCHING AND POLYMERIZATION DEPOSITION RATES IN DIFFERENT RADIAL GAS INJECTION ZONES BY APPLYING TIME MODULATION

摘要

PROBLEM TO BE SOLVED: To provide an etching method and apparatus with a uniform etching rate or etching profile that prevents gas dwell time from becoming relatively shorter at the central portion than at the peripheral portion. SOLUTION: This plasma etching treatment is performed in a plasma reaction apparatus with a ceiling electrode 110 that lies on a process region equipped with multiple injection zones shaped as concentric circles. This plasma etching treatment includes distribution of chemical species among multiple gas injection zones by injecting treatment gases of different chemical species composition through different gas injection zones. The treatment gases comprise fluorine rich polymer-forming etching gas that promotes a high etching rate, carbon rich polymer-forming etching gas that promotes a high polymerization deposition rate, polymer control gas (such as oxygen or nitrogen) that delays polymerization deposition rate, and inactive dilution gas that alleviates tapering-off of etching profile. COPYRIGHT: (C)2008,JPO&INPIT