Hostname: page-component-78c5997874-ndw9j Total loading time: 0 Render date: 2024-11-06T04:48:57.570Z Has data issue: false hasContentIssue false
  • English
  • Français

Defect Reduction in Laser Thermal Processing

Published online by Cambridge University Press:  17 March 2011

Heather Banisaukas ,
Kevin S. Jones ,
Somit Talwar ,
Scott Falk  and
Dan F. Downey
Heather Banisaukas
Affiliation:
Department of Materials Science and Engineering SWAMP CenterUniversity of FloridaGainesville, FL 32611
Kevin S. Jones
Affiliation:
Department of Materials Science and Engineering SWAMP CenterUniversity of FloridaGainesville, FL 32611
Somit Talwar
Affiliation:
Verdant Technologies San Jose, CA
Scott Falk
Affiliation:
Varian Semiconductor Equipment Associates Gloucester, MA
Dan F. Downey
Affiliation:
Varian Semiconductor Equipment Associates Gloucester, MA
Get access

Abstract

Laser thermal processing (LTP) of Si involves laser melting a preamorphized layer in order to activate dopants and create a low resistivity contact. Defects are often observed to form during the recrystallization of the molten layer. This work focuses on varying the implant conditions and the pre-LTP annealing conditions in an effort to reduce these defect concentrations. The effect of very low temperature anneals (VLTA) and varying dose rates on the amorphous/crystalline interface roughness prior to LTP and the defect density after LTP have been investigated. The amorphous layer was created by a 10 keV 1×1015/cm2 Si+ implant. VLTA were conducted in a nitrogen gas furnace at temperatures between 400°C and 450°C for times between 5 minutes and 60 minutes. These anneals were chosen to minimize recrystallization of the amorphous layer by solid phase epitaxial regrowth. Variation in the dose rate from 0.06 mA/cm2 to 0.48 mA/cm2 was achieved by changing the beam current in the ion implanter. High-resolution crosssectional transmission electron microscopy (HR-XTEM) was used to analyze the effect of the VLTA or dose rate on the amorphous/crystalline interface. Results show that the 400°C 60 minute VLTA or the 0.48 mA/cm2 dose rate reduced the roughness of the amorphous/crystalline interface from over 45Å to around 15Å. This reduction in amorphous/crystalline interface roughness prior to laser thermal processing results in a reduction in LTP recrystallization defects by as much as an order of magnitude.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 610: Symposium B – Si Front End Processing - Physics & Technology..II , 2000 , B10.3
Copyright
Copyright © Materials Research Society 2000

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 Talwar, S., Verma, G., Weiner, K. H., Ion Implantation Technology, 1171–1174 (1998).Google Scholar
2 Jones, K. S., Banisaukas, H., Glassberg, J., Andideh, E., Jasper, C., Hoover, A., Agarwal, A., and Rendon, M., Appl. Phys. Lett., 75, 3659–3661 (1999).10.1063/1.125420Google Scholar
3 Sands, T., Washburn, J., Myers, E., Sadana, D. K., Nucl. Inst. And Meth. In Phys. Res., B7/8, 337–341 (1985).10.1016/0168-583X(85)90577-4Google Scholar
4 Myers, E., Rozgonyi, G. A., Sadana, D. K., Maszara, W., Wortman, J. J., and Narayan, J., MRS Fall (1985).Google Scholar
5 Rozgonyi, G. A., Myers, E., and Sadana, D. K., ECS (1986).Google Scholar
6 Wiiliams, J. S. and Poate, J. M., Ion Implantation and Beam Processing (Academic Press, Sidney, 1984).Google Scholar
7 Robertson, L. S., Lilak, A., Law, M. E., Jones, K. S., Kringhoj, P. S., Rubin, L. M., Jackson, J., Simons, D. S., and Chi, P., Appl. Phys. Lett., 71, 3105–3107 (1997).10.1063/1.120260Google Scholar
8 Jones, E. C. and Ishida, E., Mat. Sci. and Eng. Rep., R24, 1, (1998).10.1016/S0927-796X(98)00013-8Google Scholar
9 Jones, K. S. and Venables, D., J. Appl Phys., 69, 2931–2937 (1991).10.1063/1.348603Google Scholar
10 Morehead, F. F. Jr, and Crowder, B. L., Radiat. Eff., 6, 27 (1970).10.1080/00337577008235042Google Scholar
11 Tian, S., Yang, S.-H., Morris, S., Parab, K., Tasch, A. F., Kamenitsa, D., Reece, R., Freer, B., Simonton, R. B., and Magee, C., Nucl. Instrum. Methods Phys. Res. B 112, 144 (1996).10.1016/0168-583X(95)01280-XGoogle Scholar
12 Cannavo, S., Ferla, A. La, Campisano, S. U., Rimini, E., Ferla, G., Gandolfi, L., Liu, J., and Servidori, M., Mater. Res. Soc. Symp. Proc. 51 (1986).Google Scholar