• Dawson, Md
• Guilhabert, Benoit Jack Eloi
• Tamargo, Maria C.
• Watson, Ian
• Chappell, George A.
• Hastie, Jennifer E.
• Zhao, Kuaile
• Garcia, Thor

Abstract

<p>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-pm-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 &lt; 2 nm over 400 |jm², 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.</p>

Topics

• impedance spectroscopy
• surface
• photoluminescence
• crack
• II-VI semiconductor
• dry etching