Plasma texturing of multicrystalline silicon for solar cell using remote-type pin-to-plate dielectric barrier discharge

Abstract

Multicrystalline silicon (mc-Si) was etched using a pin-to-plate-type remote dielectric barrier discharge, and the effect of adding NF3 to N2 (40 slm) and O2 to N2 (40 slm)/NF3 (1 slm) on the characteristics of mc-Si etching and texturing was investigated. The addition of NF3 at flow rates up to that of N2 increased the mc-Si etch rate continuously by increasing the number of F radicals in the gas mixture. Furthermore, the addition of O2 at flow rates of up to 400 sccm to N2 (40 slm)/NF3 (1 slm) further increased the mc-Si etch rate by more than two times (749.6 nm/scan, 0.25 m min−1), as compared with that without oxygen by the further dissociation of NF3 caused by oxygen. In particular, the addition of O2 to N2/NF3 increased the surface roughness, due to the micromasking (local surface oxidation) effect and, by adding 600 sccm O2, a reflectance of 20–30% in the visible wavelength could be obtained due to the formation of optimal wave-type surface morphology.