Hostname: page-component-cd9895bd7-mkpzs Total loading time: 0 Render date: 2024-12-27T00:20:02.601Z Has data issue: false hasContentIssue false

Selective Silicon-Germanium Source/Drain Technology for Nanoscale Cmos

Published online by Cambridge University Press:  01 February 2011

M. C. Öztürk
Affiliation:
North Carolina State University Department of Electrical & Computer Engineering Centennial Campus, EGRC Building, Campus Box 7920 Raleigh, NC 27695–7920, USA
N. Pesovic
Affiliation:
North Carolina State University Department of Electrical & Computer Engineering Centennial Campus, EGRC Building, Campus Box 7920 Raleigh, NC 27695–7920, USA
J. Liu
Affiliation:
North Carolina State University Department of Electrical & Computer Engineering Centennial Campus, EGRC Building, Campus Box 7920 Raleigh, NC 27695–7920, USA
H. Mo
Affiliation:
North Carolina State University Department of Electrical & Computer Engineering Centennial Campus, EGRC Building, Campus Box 7920 Raleigh, NC 27695–7920, USA
I. Kang
Affiliation:
North Carolina State University Department of Electrical & Computer Engineering Centennial Campus, EGRC Building, Campus Box 7920 Raleigh, NC 27695–7920, USA
S. Gannavaram
Affiliation:
North Carolina State University Department of Electrical & Computer Engineering Centennial Campus, EGRC Building, Campus Box 7920 Raleigh, NC 27695–7920, USA
Get access

Abstract

Future CMOS technology nodes bring new challenges to formation of source/drain junctions and their contacts. To avoid MOSFET performance degradation with scaling, series resistance contribution of each junction must be limited to five percent of the device channel resistance. This requires ultra-shallow junctions with extremely low sheet, spreading and contact resistance. In this paper, we present an overview of the SiGe junction technology recently proposed by this laboratory for nanoscale CMOS. The technology is based on selective deposition of boron or phosphorus doped SiGe alloys in source/drain regions isotropically etched to the desired junction depth. Since the dopant atoms naturally occupy the substitutional sites during growth, the need for an activation anneal is completely eliminated limiting the maximum process temperature to 550°C for boron and 750°C for phosphorus. In this temperature range, dopant diffusion is virtually eliminated resulting in extremely abrupt doping profiles. Elimination of the high temperature implant anneal also makes the process compatible with the thermal stability needs of future high-K gate dielectrics. A key advantage of the technology is its potential to reduce the junction contact resistance. SiGe provides a smaller bandgap under the metal contact resulting in a smaller metal-semiconductor barrier height. Since the contact resistivity is an exponential function of the barrier height, the technology provides a significant advantage in reducing the contact resistivity. The results to date indicate that the technology is a promising alternative for nanoscale CMOS source/drain junctions and their contacts.

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.International Technology Roadmap for Semiconductors, 2001 Edition, Front End ProcessesGoogle Scholar
2. Gannavaram, S., Pesovic, N. and Ozturk, M.C., IEDM Technical Digest, 437, (2000).Google Scholar
3. Olson, G. L. and Roth, J. A., Mat. Sci. Reports, 3, 178 (1988)Google Scholar
4. Yu, B., Wang, Y., Wang, H., Xiang, Q., Riccobene, C., Talwar, S., and Lin, M. R., IEDM Tech. Digest, 509-512 (1999)Google Scholar
5. Talwar, S., Wang, Y., and Gelatos, C., Electrochem. Soc. Symp. Proc., 95-105 (2000)Google Scholar
6. Eyal, A., et al, Appl. Phys. Lett., 69 (1), 1996, 6466 Google Scholar
7. Liu, J., Mo, H. & Ozturk, M.C., presented at MRS 2002 Spring Meeting, San Fransisco, CA, (unpublished)Google Scholar