Suspension and transfer printing of ZnCdMgSe membranes from an InP substrate

• Published in: Optical materials express 2020-12, Vol.10 (12), p.3328
• Main Authors: Chappell, George A., Guilhabert, Benoit, Garcia, Thor, Zhao, Kuaile, Watson, Ian M., Dawson, Martin D., Tamargo, Maria C., Hastie, Jennifer E.
• Format: Article
• Language: English
• Subjects: Bowing; Cracks; Diamonds; II-VI semiconductors; Indium phosphides; Lattice matching; Membranes; Miniaturization; Optical pumping; Photoluminescence; Red shift; Substrates; Surface roughness; Transfer printing
• ISSN: 2159-3930; 2159-3930
• DOI: 10.1364/OME.411613

Wide bandgap II-VI semiconductors, lattice-matched to InP substrates, show promise for use in novel, visible wavelength photonic devices; however, release layers for substrate removal are still under development. An under-etch method is reported which uses an InP substrate as an effective release layer for the epitaxial lift-off of lattice-matched ZnCdMgSe membranes. An array of 100-µm-square membranes is defined on a ZnCdMgSe surface using dry etching and suspended from the InP substrate using a three-step wet etch. The ZnCdMgSe membranes are transfer-printed onto a diamond heatspreader and have an RMS surface roughness < 2 nm over 400 µm 2 , similar to the epitaxial surface. Membranes on diamond show a photoluminescence peak at ∼520 nm and a thermal redshift of 4 nm with ∼3.6 MWm −2 continuous optical pumping at 447 nm. Effective strain management during the process is demonstrated by the absence of cracks or visible membrane bowing and the high brightness photoluminescence indicates a minimal non-radiative defect introduction. The methodology presented will enable the heterogeneous integration and miniaturization of II-VI membrane devices.