Effects of gate-last and gate-first process on deep submicron inversion-mode InGaAs n-channel metal-oxide-semiconductor field effect transistors

J. J. Gu, Birck Nanotechnology Center, Purdue University
Y. Q. Wu, Birck Nanotechnology Center, Purdue University
Peide D. Ye, Birck Nanotechnology Center, Purdue University

Date of this Version



J. Appl. Phys. 109, 053709 (2011)


Copyright (2011) American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in J. Appl. Phys. 109, 053709 (2011) and may be found at http://dx.doi.org/10.1063/1.3553440. The following article has been submitted to/accepted by Journal of Applied Physics. Copyright (2011) J. J. Gu, Y. Q. Wu and P. D. Ye. This article is distributed under a Creative Commons Attribution 3.0 Unported License.


Recently, encouraging progress has been made on surface-channel inversion-mode In-rich InGaAs NMOSFETs with superior drive current, high transconductance and minuscule gate leakage, using atomic layer deposited (ALD) high-k dielectrics. Although gate-last process is favorable for high-k/III-V integration, high-speed logic devices require a self-aligned gate-first process for reducing the parasitic resistance and overlap capacitance. On the other hand, a gate-first process usually requires higher thermal budget and may degrade the III-V device performance. In this paper, we systematically investigate the thermal budget of gate-last and gate-first process for deep-submicron InGaAs MOSFETs. We conclude that the thermal instability of (NH(4))(2)S as the pretreatment before ALD gate dielectric formation leads to the potential failure of enhancement-mode operation and deteriorates interface quality in the gate-first process. We thus report on the detailed study of scaling metrics of deep-submicron self-aligned InGaAs MOSFET without sulfur passivation, featuring optimized threshold voltage and negligible off-state degradation. (C) 2011 American Institute of Physics. [doi:10.1063/1.3553440]


Nanoscience and Nanotechnology