skip to main content

SciTech ConnectSciTech Connect

Title: Method for Determining Average Damage Depth of Sawn Crystalline Silicon Wafers

The depth of surface damage (or simply, damage) in crystalline silicon wafers, caused by wire sawing of ingots, is determined by performing a series of minority carrier lifetime (MCLT) measurements. Samples are sequentially etched to remove thin layers from each surface and MCLT is measured after each etch step. The thickness-removed ( at which the lifetime reaches a peak value corresponds to the damage depth. This technique also allows the damage to be quantified in terms of effective surface recombination velocity (Seff). To accomplish this, the MCLT data are converted into an Seff vs plot, which represents a quantitative distribution of the degree of damage within the surface layer. We describe a wafer preparation procedure to attain reproducible etching and MCLT measurement results. We also describe important characteristics of an etchant used for controllably removing thin layers from the wafer surfaces. Some typical results showing changes in the MCLT vs plots for different cutting parameters are given.
; ;
Publication Date:
OSTI Identifier:
Report Number(s):
Journal ID: empty
DOE Contract Number:
Resource Type:
Journal Article
Resource Relation:
Journal Name: Review of Scientific Instruments; Journal Volume: 87; Journal Issue: 4; Related Information: Review of Scientific Instruments
Research Org:
NREL (National Renewable Energy Laboratory (NREL), Golden, CO (United States))
Sponsoring Org:
USDOE Office of Energy Efficiency and Renewable Energy (EERE)
Country of Publication:
United States
14 SOLAR ENERGY; 36 MATERIALS SCIENCE etching; dislocations; electron hole recombination; passivation; slurries