Array of Graphene Variable Capacitors on 100 mm Silicon Wafers for Vibration-Based Applications

Highly flexible, electrically conductive freestanding graphene membranes hold great promise for vibration-based applications. This study focuses on their integration into mainstream semiconductor manufacturing methods. We designed a two-mask lithography process that creates an array of freestanding...

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Bibliographic Details
Main Authors: Millicent N. Gikunda, Ferdinand Harerimana, James M. Mangum, Sumaya Rahman, Joshua P. Thompson, Charles Thomas Harris, Hugh O. H. Churchill, Paul M. Thibado
Format: Article
Language:English
Published: MDPI AG 2022-05-01
Series:Membranes
Subjects:
Online Access:https://www.mdpi.com/2077-0375/12/5/533
Description
Summary:Highly flexible, electrically conductive freestanding graphene membranes hold great promise for vibration-based applications. This study focuses on their integration into mainstream semiconductor manufacturing methods. We designed a two-mask lithography process that creates an array of freestanding graphene-based variable capacitors on 100 mm silicon wafers. The first mask forms long trenches terminated by square wells featuring cone-shaped tips at their centers. The second mask fabricates metal traces from each tip to its contact pad along the trench and a second contact pad opposite the square well. A graphene membrane is then suspended over the square well to form a variable capacitor. The same capacitor structures were also built on 5 mm by 5 mm bare dies containing an integrated circuit underneath. We used atomic force microscopy, optical microscopy, and capacitance measurements in time to characterize the samples.
ISSN:2077-0375