Open AccessDry Phosphorus silicate glass etching and surface conditioning and cleaning for multi-crystalline silicon solar cell processing
Author(s) -
Ahmed S Kagilik
Publication year - 2014
Publication title -
al-ṭāqaẗ al-s̆amsiyyaẗ wa-al-tanmiyyaẗ al-mustadāmaẗ/solar energy and sustainable development
Language(s) - English
Resource type - Journals
eISSN - 2414-6013
pISSN - 2411-9636
DOI - 10.51646/jsesd.v3i1.87
Subject(s) - solar cell , etching (microfabrication) , wafer , plasma enhanced chemical vapor deposition , materials science , dry etching , silicate , silicon nitride , silicon , isotropic etching , chemical vapor deposition , reactive ion etching , chemical engineering , plasma etching , analytical chemistry (journal) , layer (electronics) , chemistry , composite material , nanotechnology , optoelectronics , environmental chemistry , engineering
As an alternative to the wet chemical etching method, dry chemical etching processes for Phosphorus silicate glass (PSG) layer removal using Trifuormethane /Sulfur Hexafuoride (CHF 3/SF6) gas mixture in commercial silicon-nitride plasma enhanced chemical vapour deposition (SiN-PECVD) system is applied. T e dependence of the solar cell performance on the etching temperature is investigated and optimized. It is found that the SiN-PECVD system temperature variation has a significant impact on the whole solar cell characteristics. A dry plasma cleaning treatment of the Si wafer surface after the PSG removal step is also investigated and developed. The cleaning step is used to remove the polymer f lm which is formed during the PSG etching using both oxygen and hydrogen gases.By applying an additional cleaning step, the polymer film is deposited on the silicon wafer surface after PSG etching is eliminated. T e effect of different plasma cleaning conditions on solar cell performance is investigated. Af er optimization of the plasma operating conditions, the performance of the solar cell is improved and the overall gain in efficiency of 0.6 % absolute is yielded compared to a cell without any further cleaning step. On the other hand, the best solar cell characteristics can reach values close to that achieved by the conventional wet chemical etching processes demonstrating the effectiveness of the additional O2/H2 post cleaning treatment