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arXiv · 1510.07236

Ge Microdisk with Lithographically-Tunable Strain using CMOS-Compatible Process

David S. Sukhdeo·Jan Petykiewicz·Shashank Gupta·Daeik Kim·Sungdae Woo·Youngmin Kim·Jelena Vuckovic·Krishna C. Saraswat·Donguk Nam
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Abstract

We present germanium microdisk optical resonators under a large biaxial tensile strain using a CMOS-compatible fabrication process. Biaxial tensile strain of ~0.7% is achieved by means of a stress concentration technique that allows the strain level to be customized by carefully selecting certain lithographic dimensions. The partial strain relaxation at the edges of a patterned germanium microdisk is compensated by depositing compressively stressed silicon nitride layer. Two-dimensional Raman spectroscopy measurements along with finite-element method simulations confirm a relatively homogeneous strain distribution within the final microdisk structure. Photoluminescence results show clear optical resonances due to whispering gallery modes which are in good agreement with finite-difference time-domain optical simulations. Our bandgap-customizable microdisks present a new route towards an efficient germanium light source for on-chip optical interconnects.

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David S. Sukhdeo, Jan Petykiewicz, Shashank Gupta, Daeik Kim, Sungdae Woo, Youngmin Kim, Jelena Vuckovic, Krishna C. Saraswat, Donguk Nam. 2015-10-25. Ge Microdisk with Lithographically-Tunable Strain using CMOS-Compatible Process. https://doi.org/10.1364/oe.23.033249

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