13 October 2015 Capacitive effective thickness of a few nanometers by atomic layer deposition and device performance in Ge gate-all-around fin field effect transistors
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Abstract
Ge gate-all-around fin field-effect transistors (Ge FinFETs) with a capacitive effective thickness of a few nanometers have been successfully achieved via atomic-layer-deposited (ALD) high-dielectric Al2O3 on GeO2/Ge and by adopting low-cost thermo ALD equipment. The MOS interface properties of the ZrO2 or Al2O3/GeO2/Ge structures have been studied systematically. It has been found that a GeO2 interfacial layer that is greater than approximately 2.5 nm results in a significant degradation of the MOS interfaces, while an equivalent oxide thickness of <3  nm is still possible while maintaining good GeO2/Ge interface quality. The Ge FinFET’s value has been demonstrated with the Al2O3/GeO2/Ge gate stack prepared using a thermal ALD layer of Al2O3. The experimental results indicate that the MOS interface quality obtained with the technique developed for high-permittivity/Ge gate stacks is also extremely useful for the fabrication of triangle-fin complementary metal oxide semiconductor devices. An Ion/Ioff ratio of 3.2×104 and a subthreshold swing of 103  mV/dec were obtained for the triangular n-type Ge gate-all-around FET with (111) sidewalls. The drain current at VGSVT=VDS=−1.5  V is 88  mA/mm.
© 2015 Society of Photo-Optical Instrumentation Engineers (SPIE)
Chu-Lin Chu, Bo-Yuan Chen, Yiin-Kuen Fuh, "Capacitive effective thickness of a few nanometers by atomic layer deposition and device performance in Ge gate-all-around fin field effect transistors," Journal of Micro/Nanolithography, MEMS, and MOEMS 14(4), 044501 (13 October 2015). https://doi.org/10.1117/1.JMM.14.4.044501 . Submission:
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