Browsing by Author "Kuo, Po-Shen"

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Electrical properties of SiGe nanowire following fluorine/nitrogen plasma treatment
(2014-01-15)
Chang, Kow-Ming
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Chen, Chu-Feng
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Lai, Chiung-Hui
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Kuo, Po-Shen
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Chen, Yi-Ming
The improvements to electrical properties of SiGe nanowires by surface plasma treatment were investigated. Various durations of pre-oxidation with fluorine; ambients for post-nitridation plasma treatment, and annealing temperature after plasma treatment, 800-950 degrees C, were applied. Pre-oxidation treatment using fluorine plasma; improved the conductance of SiGe nanowires because the Si-F binding energy created a more stable interface state than bare nanowire on the surface of SiGe. N-2 plasma incorporated more N than does in NH3 plasma, and NH3 has the drawback of introducing electron traps, causing Si-H bonds to break in the subsequent annealing process. Since the reparation of surface defects by plasma treatment is valid, the high post-annealing temperature to reduce defect by re-crystallizing can be reduced. Hence, Ge diffusion at low post-annealing temperature did not reduce the high concentration of Ge at the SiGe nanowire surfaces. (C) 2013 Elsevier B.V. All rights reserved.
Influence of Surface State on Biochemical Sensing Using SiGe Nanowire
(2015-06-01)
Lai, Chiung-Hui
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Chang, Kow-Ming
;
Chen, Yi-Ming
;
Chen, Chu-Feng
;
Kuo, Po-Shen
Nanowires are extensively used to fabricate highly sensitive electrical sensors for detection of biological and chemical species. The hole mobility can be promoted by the increasing Ge fraction in SiGe, achieved by the oxidation-induced Ge condensation. However, oxidation increases the number of surface states, which brings the nonnegligible contribution in mobility degradation. In this work, 3-aminopropyltrimethoxysilane (APTMS) was used as a biochemical reagent to modify the surface of SiGe nanowires, then bonding to bio-linker, bis (3-sulfo-N-hydroxysuccinimide ester) sodium salt (BS3). Various methods have been proposed for increasing sensitivity of boron-doped SiGe nanowires, such as capping layer, surface treatment, and annealing temperature.