PLASMA REMEDIATION OF GREENHOUSE GASES IN SEMICONDUCTOR PROCESSING

Semiconductor microelectronics fabrication uses plasma processing for etching and deposition. These processes use gases which have large global warming potentials. In etching and chamber cleaning, Perfluorinated compounds (PFCs), typically including CF₄, C₂F₆, CHF₃, NF₃, SF₆ and C₃F₈, are used to generate reactive F atoms. Due to underutilization of the feedstock gases or secondary production of species, the effluent from the reactor contains many of these gases. A plasma remediation method for abating PFC emissions is presented.

We have used the Hybrid Plasma Equipment Model to simulate the dissociation of feedstock greenouse gases in an inductively coupled plasma reactor, and their subsequent remediation in a downstream "burn-box".

We consider Ar/CF₄ as the process gas mixture with O₂ injected downstream to facilitate oxidation of the undissociated CF₄, gas phase reaction products (e.g., C₂F₆, C₂F₄) and etch product (SiF₄). The electron density is shown for a combined plasma etching chamber and downstream burn-box.