1. Department of Materials Science and Engineering, North Carolina State University, Raleigh, North Carolina 27695-7916, United States of America
2. Sumitomo Metal Industries, Limited, Research and Development Center, Silicon Manufacturing and Engineering Subdivision, Sumitomo Sitix Division, Saga 849-0597, Japan
3. Sumitomo Metal Industries, Limited, Advanced Technology Research Laboratories, Amagasaki 660-0891, Japan