This paper discusses the gettering process during emitter diffusion in upgraded metallurgical grade
(UMG) silicon and the effect of a subsequent low temperature annealing (LTA) which is proven to be a suitable
method to increase the cell lifetime and efficiency according to recent studies from other authors. Neighboring wafers
of the same ingot were selected to be processed and characterized by means of μW-PCD lifetime measurements. An
increase in minority carrier lifetime by a factor of 3.8 is obtained after the phosphorus gettering, although no
improvement due to the LTA process in these wafers was observed.