Surface wave plasma abatement of CHF3 and CF4 containing semiconductor process emissions

Projected exponential growth in semiconductor device manufacture over the n ext few years demands technology to reduce the corresponding increase in et chants such as perfluorocompounds (PFCs), CHF3, and SF6 that would be emitt ed into the atmosphere. These compounds are a cause for concern because of their large global warming potentials relative to CO2 and of their long lif etimes in the atmosphere, often tens of thousands of years. We demonstrate that a plasma-based technology can yield effective (up to 99.9%) destructio n and removal efficiencies (DREs) for CF4 and CHF3 present in etch recipes widely used in the semiconductor industry. Specifically, we report applicat ion of surface wave plasmas at 2.45 GHz for this purpose. Post-plasma efflu ent analysis included the determination of DREs and product distributions, simultaneously by gas-phase FTIR and QMS. Application of microwave powers f rom 500 to 1950 W were investigated and DREs for CF4 and CHF3 reported. Fin al product analysis indicated that PFC conversion was limited to low molecu lar weight gases such as CO2, CO, COF2, H2O, and HF. These investigations d emonstrate that surface wave plasma destruction of the referenced PFCs at t he output of semiconductor etch tools is a viable nonintrusive point of use abatement technology.