Electrical characterization of high performance, liquid gated vertically stacked SiNW-based 3D FET biosensors

SENSORS AND ACTUATORS B-CHEMICAL

卷:199

Article

Buitrago, Elizabeth¹  Badia, Montserrat Fernandez-Bolanos^1,2,3  Georgiev, Yordan M.⁴  Yu, Ran⁴  Lotty, Olan⁴  Holmes, Justin D.⁴  Nightingale, Adrian M.⁵  Guerin, Hoel M.¹  Ionescu, Adrian M.¹ 

[1] Ecole Polytech Fed Lausanne, Nanoelect Devices Lab Nanolab, CH-1015 Lausanne, Switzerland

[2] IBM Res Zurich, CH-8803 Ruschlikon, Switzerland

[3] Natl Univ Ireland Univ Coll Cork, Mat Chem & Anal Grp, Dept Chem, Cork, Ireland

[4] Natl Univ Ireland Univ Coll Cork, Tyndall Natl Inst, Cork, Ireland

[5] Univ London Imperial Coll Sci Technol & Med, London SW7 2AZ, England

关键词: ISFET;    Sensor;    FinFET;    SiNW;    GAA;    Ion sensitive field effect transistor;   

DOI  :  10.1016/j.snb.2014.03.099

来源: Elsevier

【 摘 要 】

A 3D vertically stacked silicon nanowire (SiNW) field effect transistor featuring a high density array of fully depleted channels gated by a backgate and one or two symmetrical platinum side-gates through a liquid has been electrically characterized for their implementation into a robust biosensing system. The structures have also been characterized electrically under vacuum when completely surrounded by a thick oxide layer. When fully suspended, the SiNWs may be surrounded by a conformal high-K gate dielectric (HfO2) or silicon dioxide. The high density array of nanowires (up to 7 or 8 x 20 SiNWs in the vertical and horizontal direction, respectively) provides for high drive currents (1.3 mA/mu m, normalized to an average NW diameter of 30 nm at V-SG = 3 V, and V-d = 50 mV, for a standard structure with 7 x 10 NWs stacked) and high chances of biomolecule interaction and detection. The use of silicon on insulator substrates with a low doped device layer significantly reduces leakage currents for excellent I-on/I-off ratios >10(6) of particular importance for low power applications. When the nanowires are submerged in a liquid, they feature a gate all around architecture with improved electrostatics that provides steep subthreshold slopes (SS <75 mV/dec), low drain induced barrier lowering (DIBL < 20 mV/V) and high transconductances (g(m) > 10 mu S) while allowing for the entire surface area of the nanowire to be available for biomolecule sensing. The fabricated devices have small SiNW diameters (down to d(NW) similar to 15-30 nm) in order to be fully depleted and provide also high surface to volume ratios for high sensitivities. (C) 2014 Elsevier B.V. All rights reserved.

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