High quality single crystal Ge nano-membranes for opto-electronic integrated circuitry

Abstract

Copyright and reuse:The Warwick Research Archive Portal (WRAP) makes this work by researchers of the University of Warwick available open access under the following conditions. Copyright © and all moral rights to the version of the paper presented here belong to the individual author(s) and/or other copyright owners. To the extent reasonable and practicable the material made available in WRAP has been checked for eligibility before being made available.Copies of full items can be used for personal research or study, educational, or not-forprofit purposes without prior permission or charge. Provided that the authors, title and full bibliographic details are credited, a hyperlink and/or URL is given for the original metadata page and the content is not changed in any way. Publisher's statement:Copyright ( A note on versions:The version presented in WRAP is the published version or, version of record, and may be cited as it appears here.For more information, please contact the WRAP A thin, flat, and single crystal germanium membrane would be an ideal platform on which to mount sensors or integrate photonic and electronic devices, using standard silicon processing technology. We present a fabrication technique compatible with integrated-circuit wafer scale processing to produce membranes of thickness between 60 nm and 800 nm, with large areas of up to 3.5 mm 2 . We show how the optical properties change with thickness, including appearance of Fabry-Perot type interference in thin membranes. The membranes have low Q-factors, which allow the platforms to counteract distortion during agitation and movement. Finally, we report on the physical characteristics showing sub-nm roughness and a homogenous strain profile throughout the freestanding layer, making the single crystal Ge membrane an excellent platform for further epitaxial growth or deposition of materials. V C 2014 AIP Publishing LLC. [http://dx

Atmospheric pressure metal organic chemical vapor deposition of thin germanium films

“…Due to the optical properties of thin germanium films, it is possible to determine the film thickness by vis-NIR measurements (Figs. 8-10) as was demonstrated recently [71]. This method is particularly interesting, since in contrast to AFM studies the film is not destroyed for or by the measurement (method B).…”

Ultrasonic Inspection and Self-Healing of Ge and 3C-SiC Semiconductor Membranes

“…The first deposition temperature was 400 • C for the first 100 nm thick Ge layer, then the following layer was grown at 670 • C, and a final anneal was carried out at a temperature of 830 • C for 10 minutes to improve the crystal quality of the Ge epilayer. More growth details are available in references [32], [35], [36].…”

Micro and nanofabrication of SiGe/Ge bridges and membranes by wet-anisotropic etching

“…TMAH and KOH allow a high selectivity between etching rates in h0 0 1i and h1 1 1i directions in the silicon bulk [12]. For this reason they have been widely used in order to create suspended structures, for example by an etch against the etch-resistive {1 1 1} planes in Si(0 0 1) substrates [16,17] or by exploiting the underetching rates of a Si(0 0 1) substrate [18,19]. Germanium is extremely chemically resistive against KOH or TMAH [20,21], so it is potentially an excellent material for this kind of micromachining.…”