Tabula Rasa: Oxygen precipitate dissolution though rapid high temperature processing in silicon

Abstract

Over one fourth of all monocrystalline silicon ingots suffer from a 20% performance degradation due to oxygen precipitates. Tabula Rasa (TR) is a mitigation technique that dissolves these precipitates, making them harmless. This work explores the dependence of oxygen dissolution on annealing time and temperature for the TR process to aid in solar cell process optimization. The dissolution time for oxygen precipitates was found to be more than 10 minutes for total dissolution, longer than normal TR process times in the electronics industry. The activation energy, extracted from the precipitate dissolution curves, is found to be 2.6 +- 0.5 eV. This value when compared to the migration enthalpy of oxygen in silicon can be used to reveal the energy limiting proces in TR.