PLASMA ETCH PROCESS USING POLYMERIZING ETCH GASES WITH DIFFERENT ETCH AND POLYMER-DEPOSITION RATES IN DIFFERENT RADIAL GAS INJECTION ZONES WITH TIME MODULATION

摘要

A plasma etching process using polymerizing etch gas with different etch rates and polymer-depositing rates in different radial gas injection zones using time modulation is provided to improve the distribution of non-uniform etch rate in the central region of a wafer by using a polymerized etch gas with different etch rates and polymer-deposition rates of a capacitive plasma etch process for etching a dielectric thin film. A plasma etch process for etching a processed article is performed in a plasma reaction chamber including a sealing electrode over a process region with a plurality of concentric gas injection zones, including a process gas injection process in which process gas having chemical species of different composition is injected through different gas injection zones among the gas injection zones so that distribution of chemical species between the gas injection zones is determined. The process gas includes fluorine-enriched polymerized etch gas, carbon-enriched polymerized etch gas for accelerating a high polymer deposition rate, polymer management gas for lowering the deposition of polymer, and inert diluent gas for reducing etch profile tapering.