Dual-Sacrificial-Layer Wet Etching for Transfer Printing of InP-Based Antimony-Containing Materials

We report a dual-sacrificial-layer-based lateral wet etching scheme for the heterogeneous integration of InP-based antimony-containing GaAsSb, InGaAsSb, and AlGaAsSb materials on foreign substrates such as Si. For a proof-of-concept demonstration, only ternary lattice-matched GaAsSb is investigated here. Two wet etchants based on HCl and HF are employed, and the associated results are compared in terms of etch rates, selectivity, and surface roughness. A dual sacrificial layer comprising lattice-matched InAlAs and InP was also employed in this study, and it allows for effective etching by HCl as confirmed by surface smoothness and high selectivity. During the transfer printing process, lateral wet etching of the sacrificial layer is accomplished in as little as 30 min to produce a clean etch profile for a coupon size of 300 × 300 μm. The successful GaAsSb transfer on silicon substrates is then vetted by both material and device level characterizations, suggesting satisfactory bonding due to clean and smooth wet etching profiles. The developed wet etching technique would facilitate next-generation InP-based electronic and optoelectronic devices.