Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

A method for determining average damage depth of sawn crystalline silicon wafers

Journal Article · · Review of Scientific Instruments
DOI:https://doi.org/10.1063/1.4944792· OSTI ID:1248799
 [1];  [2];  [2]
  1. National Renewable Energy Lab. (NREL), Golden, CO (United States)
  2. National Renewable Energy Lab. (NREL), Golden, CO (United States); New Jersey Inst. of Technology, Newark, NJ (United States)

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 (δt) 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 δt 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. Lastly, some typical results showing changes in the MCLT vs δt plots for different cutting parameters are given.

Research Organization:
National Renewable Energy Laboratory (NREL), Golden, CO (United States)
Sponsoring Organization:
USDOE Office of Energy Efficiency and Renewable Energy (EERE)
Grant/Contract Number:
AC36-08GO28308
OSTI ID:
1248799
Alternate ID(s):
OSTI ID: 1245685
Report Number(s):
NREL/JA--5J00-66320
Journal Information:
Review of Scientific Instruments, Journal Name: Review of Scientific Instruments Journal Issue: 4 Vol. 87; ISSN 0034-6748; ISSN RSINAK
Publisher:
American Institute of Physics (AIP)Copyright Statement
Country of Publication:
United States
Language:
English

References (9)

Basic Mechanisms and Models of Multi-Wire Sawing journal July 2004
Wafering of silicon crystals journal March 2006
Development of refractory ohmic contact materials for gallium arsenide compound semiconductors journal January 2002
A macroscopic mechanical model of the wire sawing process journal September 2011
Thin Czochralski silicon solar cells based on diamond wire sawing technology journal March 2012
Rapid nondestructive technique for monitoring polishing damage in semiconductor wafers journal November 1980
Acid-Based Etching of Silicon Wafers: Mass-Transfer and Kinetic Effects journal January 2000
A New Defect Etch for Polycrystalline Silicon journal January 1984
Non-destructive evaluation methods for subsurface damage in silicon wafers: a literature review journal January 2007