Surface reaction enhancement by UV irradiation during Si etching process with chlorine atom beam

We investigated the dependence of etching rate on irradiation of photons with a UV lamp during Si etching processes with chlorine atom beam to understand the influence of UV photon irradiation in the plasma etching process. We found that UV from 220 to 380 nm drastically enhanced Si surface reactions with a chlorine atom beam at lamp power densities over 20 mW/ cm². Additionally, we were able to control the Si etching rate by changing the photon irradiation power density. These results led us to speculate that the irradiation of UV photons from 220 to 380 nm generates crystal defects on the Si surface and enhances chemical reactions between Si and chlorine during Cl ₂ plasma etching processes.