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A Comparison of Mos Devices with In-Situ Boron Doped Polysilicon and Poly Sige Gates Deposited in an Rtcvd System Using S12H6 and B2H6 Gas Mixture

Published online by Cambridge University Press:  10 February 2011

M. R. Mirabedini
Affiliation:
Department of Electrical and Computer Engineering Box 7911, North Carolina State University, Raleigh, NC 27695
V. Z-Q Li
Affiliation:
Department of Electrical and Computer Engineering Box 7911, North Carolina State University, Raleigh, NC 27695
A. R. Acker
Affiliation:
Department of Electrical and Computer Engineering Box 7911, North Carolina State University, Raleigh, NC 27695
R. T. Kuehn
Affiliation:
Department of Electrical and Computer Engineering Box 7911, North Carolina State University, Raleigh, NC 27695
D. Venables
Affiliation:
Department of Material Science and Computer Engineering Box 7907, North Carolina State University, Raleigh, NC 27695
M. C. Öztürk
Affiliation:
Department of Electrical and Computer Engineering Box 7911, North Carolina State University, Raleigh, NC 27695
J. J. Wortman
Affiliation:
Department of Electrical and Computer Engineering Box 7911, North Carolina State University, Raleigh, NC 27695
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Abstract

In this work, in-situ doped polysilicon and poly-SiGe films have been used as the gate material for the fabrication of MOS devices to evaluate their respective performances. These films were deposited in an RTCVD system using a Si2H6 and GeH4 gas mixture. MOS capacitors with 45 Å thick gate oxides and polysilicon/poly-SiGe gates were subjected to different anneals to study boron penetration. SIMS analysis and flat band voltage measurements showed much lower boron penetration for devices with poly-SiGe gates than for devices with polysilicon gates. In addition, C-V measurements showed no poly depletion effects for poly-SiGe gates while polysilicon gates had a depletion effect of about 8%. A comparison of resistivities of these films showed a low resistivity of 1 mΩ-cm for poly-SiGe films versus 3 mΩ-cm for polysilicon films after an anneal at 950 °C for 30 seconds.

Type
Research Article
Copyright
Copyright © Materials Research Society 1998

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References

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