APPARATUS AND METHODS FOR REDUCING LIGHT INDUCED DAMAGE IN THIN FILM SOLAR CELLS

摘要

Apparatus and methods for forming a silicon-containing i-layer on a substrate for a thin film photovoltaic cell are disclosed. The apparatus includes a chamber body defining a processing region containing the substrate, a hydrogen source and a silane source coupled to a plasma generation region, an RF power source that applies power at a power level in the plasma generation region to generate a plasma and deposit the silicon-containing i-layer at a selected deposition rate to a selected thickness and a controller. The controller controls the power level and the deposition rate of the i-layer on the substrate such that the thin film solar cell exhibits light induced damage that conforms to a linear fit of the product of the RF power, the deposition rate and the selected thickness of the i-layer. In accordance with further aspects of the present invention, the controller controls the RF power and the deposition rate so that a product (x) of the RF power in watts, the deposition rate of the i-layer in nm per min and the thickness of the i-layer in nm is less than a predetermined number y and satisfies the equation y = 5E11 *x + 3.3749 plus or minus a margin.