Role of Self-Assembled Monolayer Passivation in Electrical Transport Properties and Flicker Noise of Nanowire Transistors

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• 作者：Seongmin Kim ; Patrick D. Carpenter ; Rand K. Jean ; Haitian Chen ; Chongwu Zhou ; Sanghyun Ju ; David B. Janes
• 刊名：ACS Nano
• 出版年：2012
• 出版时间：August 28, 2012
• 年：2012
• 卷：6
• 期：8
• 页码：7352-7361
• 全文大小：643K
• 年卷期：v.6,no.8(August 28, 2012)
• ISSN：1936-086X

文摘

Semiconductor nanowires have achieved great attention for integration in next-generation electronics. However, for nanowires with diameters comparable to the Debye length, which would generally be required for one-dimensional operation, surface states degrade the device performance and increase the low-frequency noise. In this study, single Inb>2b>Ob>3b> nanowire transistors were fabricated and characterized before and after surface passivation with a self-assembled monolayer of 1-octadecanethiol (ODT). Electrical characterization of the transistors shows that device performance can be enhanced upon ODT passivation, exhibiting steep subthreshold slope (64 mV/dec), near zero threshold voltage (0.6 V), high mobility (624 cm²/V路s), and high on-currents (40 渭A). X-ray photoelectron spectroscopy studies of the ODT-passivated nanowires indicate that the molecules are bound to Inb>2b>Ob>3b> nanowires through the thiol linkages. Device simulations using a rectangular geometry to represent the nanowire indicate that the improvement in subthreshold slope and positive shift in threshold voltage can be explained in terms of reduced interface trap density and changes in fixed charge density. Flicker (low-frequency, 1/f) noise measurements show that the noise amplitude is reduced following passivation. The interface trap density before and after ODT passivation is profiled throughout the band gap energy using the subthreshold current鈥搗oltage characteristics and is compared to the values extracted from the low-frequency noise measurements. The results indicate that self-assembled monolayer passivation is a promising optimization technology for the realization of low-power, low-noise, and fast-switching applications such as logic, memory, and display circuitry.<br>

Keywords:

bs.acs.org/action/doSearch?action=search&searchText=octadecanethiol&qsSearchArea=searchText">octadecanethiol; bs.acs.org/action/doSearch?action=search&searchText=indium+oxide&qsSearchArea=searchText">indium oxide; bs.acs.org/action/doSearch?action=search&searchText=nanowires&qsSearchArea=searchText">nanowires; bs.acs.org/action/doSearch?action=search&searchText=flicker+noise&qsSearchArea=searchText">flicker noise; bs.acs.org/action/doSearch?action=search&searchText=transistor&qsSearchArea=searchText">transistor