Geometry-based tunability enhancement of flexible thin-film varactors

Knobelspies, S, Gonnelli, C, Vogt, C, Daus, A, Münzenrieder, N and Tröster, G (2017) Geometry-based tunability enhancement of flexible thin-film varactors. IEEE Electron Device Letters, 38 (8). pp. 1117-1120. ISSN 0741-3106

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In this letter, flexible voltage-controlled capacitors (varactors) based on an amorphous Indium–Gallium–Zinc–Oxide (a-IGZO) semiconductor are presented. Two different varactor designs and their influence on the capacitance tuning characteristics are investigated. The first design consists of a top electrode finger structure which yields a maximum capacitance tunability of 6.9 at 10 kHz. Second, a novel interdigitated varactor structure results in a maximum tunability of 93.7 at 100 kHz. The design- and frequency-dependencies of the devices are evaluated through C–V measurements. Furthermore, we show bending stability of the devices down to a tensile radius of 6 mm without altering the performance. Finally, a varactor is combined with a thin-film resistor to demonstrate a tunable RC-circuit for impedance matching and low-pass filtering applications. The device fabrication flow and material stack are compatible with standard flexible thin-film transistor fabrication which enables parallel implementation of analog or logic circuitry and varactor devices.

Item Type: Article
Additional Information: © 2017 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.
Schools and Departments: School of Engineering and Informatics > Engineering and Design
Research Centres and Groups: Sensor Technology Research Centre
Depositing User: Niko Munzenrieder
Date Deposited: 02 Aug 2017 11:22
Last Modified: 11 Feb 2022 12:28

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