Effects of Phosphorus Diffusion on Gettering of Metal Impurities in UMG Silicon Wafers

Abstract EN

Fe distributions were simulated by using impurity-to-efficiency simulator for the analysis of phosphorus diffusion gettering and confirmed the dependencies of the electron lifetime on the various gettering conditions.

It was observed that iron atoms in the Si wafer could be more efficiently gettered if the temperatures were provided to the wafer in two different steps.

That two-step gettering process was applied to an upgraded-metallurgical grade (UMG) Si wafer, and the electron lifetimes of the UMG-Si wafer were 3 μsec by applying the second temperature profile at 600°C for 420 min.

It was also confirmed that the efficiency of the UMG-Si solar cell increased 0.53% due to two-step gettering process.