Hostname: page-component-7c8c6479df-995ml Total loading time: 0 Render date: 2024-03-28T00:13:53.244Z Has data issue: false hasContentIssue false

Evaluating Amorphization Around Micro-Cracks in PV Silicon

Published online by Cambridge University Press:  31 January 2011

Prashant K. Kulshreshtha
Affiliation:
prashant.kulshreshtha@gmail.com, North Carolina State University, Materials Science and Engineering, Raleigh, North Carolina, United States
Khaled M. Youssef
Affiliation:
khaled_youssef@ncsu.edu, North Carolina State University, Materials Science and Engineering, Raleigh, North Carolina, United States
George Rozgonyi
Affiliation:
rozgonyi@ncsu.edu, North Carolina State University, Materials Science and Engineering, Raleigh, North Carolina, United States
Get access

Abstract

Since the initiation and propagation of a micro-crack in a silicon wafer introduces local variations in stress, it is critical to the understanding of wafer breakage that accurate profiling of stress be performed in the vicinity of the micro-crack. In this study, nanoindentation has been used to investigate the stress-relaxation during crack initiation and propagation in material of particular interest to the photovoltaic (PV) industry. The low load (<1 mN) capability of a Hysitron Triboindenter® was used to accurately profile the extent of plastic deformation and resulting amorphization. Measurements were made on Si samples extracted from top, middle and bottom of a (100) oriented single crystal ingot to evaluate the impact of different carbon, oxygen and metallic impurity concentrations. A gradual but significant drop in hardness from 10.2 to 6.9 GPa occurred as indents were made closer to the micro-crack and was attributed to local amorphization. Electron back scattered diffraction (EBSD) and Raman spectroscopy confirmed the amorphization, respectively, at nano- and micro-scale.

Type
Research Article
Copyright
Copyright © Materials Research Society 2010

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1 Scandian, C. et.al, Physica Status Solidi (a), 171, 6782 (1999).Google Scholar
2 Chasiotis, I. et.al, Journal of Applied Mechanics, 73, 715 (2006).Google Scholar
3 Puech, P. et.al, Journal of Material Research, 4 (19), 12731280 (2004).Google Scholar
4 Zhang, L. et.al, International Journal of Mechanical Sciences, 43, 19851996 (2001).Google Scholar
5 Minowa, K. et.al, Physical Review Letters, 2 (69), 320322 (1992).Google Scholar
6 Kermode, J. R. et.al, Nature, 455, 12241227 (2008).Google Scholar
7 Kvande, R. et.al, Materials Science and Engineering A, 413-414, 545549 (2005).Google Scholar
8 Namazu, T. et.al, Solid-State Sensors, Actuators and Microsystems Conference, 2007. TRANSDUCERS 2007. International, 627-630 (2007).Google Scholar
9 Williams, J. S. et.al, Material Research Society Symposium Proceedings, 841, R10.3.1 (2005).Google Scholar