| AVS 57th International Symposium & Exhibition | |
| Plasma Science and Technology | Thursday Sessions |
| Session PS-ThP |
| Session: | Plasma Science and Technology Poster Session |
| Presenter: | B.S. Kim, INHA University, Republic of Korea |
| Authors: | B.S. Kim, INHA University, Republic of Korea J.H. Sung, INHA University, Republic of Korea M.W. Lee, INHA University, Republic of Korea C.H. Choi, INHA University, Republic of Korea H.D. Yim, INHA University, Republic of Korea S.G. Park, INHA University, Republic of Korea S.G. Lee, INHA University, Republic of Korea E.H. Lee, INHA University, Republic of Korea B.H. O, INHA University, Republic of Korea |
| Correspondent: | Click to Email |
Polished flat silicon surfaces have high reflectivity in visible lays. The minimization of reflection losses is very important for solar cells. Lowering surface reflectivity of silicon by texturization is one of the most important processes for improving the conversion photovoltaic efficiency of silicon solar cells.
Many texturing techniques for fabricating antireflective silicon surfaces have been proposed, including mechanical diamond saw cutting, optical interference lithography, wet etching using catalysis of metal, and reactive ion etching, to produce so-called “black silicon”.
In this paper, we attempted to one step etching for formation of black silicon using combinded Cl2, C4F8, and O2 gases. It uses inductively coupled plasma (ICP) and Cl2 gas for etching, C4F8 and O2 gas for masking.
The substrate temperature was -10 °C ~ 10 °C, the fluorocarbon film deposited in a C4F8 plasma was thicker and more strongly bonded than the lower substrate temperature. Then combinded O2 gas, fluorocarbon film was locally etching which is self-masking effect. The diameter of fluorocarbon mask was dozens nanometer size.
With Cl2 etching, many processes were developed for producing vertical sidewalls, smooth surface morphology, fine critical dimension control, and high aspect ratio microstructures for MEMS. The main advantage of Cl2 etching is that etching is anisotropic since it is an ion assisted process rather than a spontaneous etching process. The subwavelength silicon pillar structure was grown up because physical etching characteristic of Cl2 plasma.
The etched silicon surface shows almost zero reflectance in the visible region. The silicon surface is covered by columnar microstructures. The diameter and height of subwavelength silicon columnar structures were depends on substrate temperature, etching, and gas contain ratio.