Hostname: page-component-76fb5796d-zzh7m Total loading time: 0 Render date: 2024-04-26T00:19:19.002Z Has data issue: false hasContentIssue false

Effect of Laser Thermal Processing on Defect Evolution in Silicon

Published online by Cambridge University Press:  01 February 2011

Erik Kuryliw
Affiliation:
Swamp Center, University of Florida Dept. of Materials Science and EngineeringP.O. Box 116130, Gainesville, FL 32611-6130
Kevin S. Jones
Affiliation:
Swamp Center, University of Florida Dept. of Materials Science and EngineeringP.O. Box 116130, Gainesville, FL 32611-6130
David Sing
Affiliation:
Motorola/International Sematech, Austin TX
Michael J. Rendon
Affiliation:
Motorola/International Sematech, Austin TX
Somit Talwar
Affiliation:
Verdant Technologies, Santa Clara CA
Get access

Abstract

Laser Thermal Processing (LTP) involves laser melting of an implantation induced preamorphized layer to form highly doped ultra shallow junctions in silicon. In theory, a large number of interstitials remain in the end of range (EOR) just below the laser-formed junction. There is also the possibility of quenching in point defects during the liquid phase epitaxial regrowth of the melt region. Since post processing anneals are inevitable, it is necessary to understand both the behavior of these interstitials and the nature of point defects in the recrystallized-melt region since they can directly affect deactivation and enhanced diffusion. In this study, an amorphizing 15 keV 1 x 1015/cm2 Si+ implant was done followed by a 1 keV 1 x 1014/cm2 B+ implant. The surface was then laser melted at energy densities between 0.74 and 0.9 J/cm2 using a 308 nm excimer-laser. It was found that laser energy densities above 0.81 J/cm2 melted past the amorphous-crystalline interface. Post-LTP furnace anneals were performed at 750°C for 2 and 4 hours. Transmission electron microscopy was used to analyze the defect formation after LTP and following furnace anneals. Secondary ion mass spectrometry measured the initial and final boron profiles. It was observed that increasing the laser energy density led to increased dislocation loop formation and increased diffusion after the furnace anneal. A maximum loop density and diffusion was observed at the end of the process window, suggesting a correlation between the crystallization defects and the interstitial evolution.

Type
Research Article
Copyright
Copyright © Materials Research Society 2002

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 Pennycook, S. J., Narayan, J., and Holland, O. W., “Point Defect Supersaturation and Enhanced Diffusion in Supersaturated Silicon Alloys,” Electrochemical Society Extended Abstracts 84 (2), 672 (1984).Google Scholar
2 Culbertson, R. J. and Pennycook, S. J., “Trapping of Interstitials During Ion Implantation in Silicon,” presented at the MRS Proceedings, Beam-Solid Interactions and Phase Transformations, Boston, MA, 1986.Google Scholar
3 Talwar, S., Verma, G., and Weiner, K., “Ultra-shallow, abrupt, and highly-activated junctions by low-energy ion implantation and laser annealing,” presented at the Ion Implant Technology, 1999.Google Scholar
4 Murto, R., Jones, K., Rendon, M. et al., “Activation and deactivation studies of laser thermal annealed boron, arsenic, phosphorus, and antimony ultra-shallow abrupt junctions,” presented at the Ion Implant Technology, 2000.Google Scholar
5 Semiconductor Industry Association, International Technology Roadmap for Semiconductors: 2001 Edition (International SEMATECH, Austin, TX, 2001).Google Scholar
6 Banisukas, H., Jones, K.S., Falk, S. et al., “Defect reduction in laser thermal processing,” presented at the Si Front-end Processing -Physics and Technology of Dopant-Defect Interactions II, San Francisco, CA, 2000.Google Scholar