Toward nanoscale Y2O3 membrane by wet chemical etching
Second quantum revolution exploiting the peculiarities of quantum physics to generate real-world tangible applications is taking place. QTs are bound to breakthrough achievements in information processing, communications, or sensing (https://qt.eu/) using new “quantum-grade” materials with unprecedent properties.
Among the different solid-state approaches, Rare-earth-ion doped crystals (REIC) appear promising due to their ultra long optical and spin coherence times. This outstanding optical and spin coherence makes REIC the state of art materials for macroscopic solid state quantum memories. Our teams recently developed new solid-state platforms based on Chemical Vapor Deposition of thin film of Eu:Y2O3 on silicon wafer. 
We would like to develop selective wet chemical etching of silicon substrate in order to obtain suspended Y2O3 membrane. The candidate will determine the best conditions (etching agent, pH, time, temperature) for the process. The challenge is to develop a reproductible process that removes selectively the silicon substrate without etching the thin film of Y2O3 (200 nm). We will also investigate the possibility to perform in situ control of the etching rate by laser transmission or reflection. Finally the Y2O3 membranes will be characterized by XRD, ellipsometry, SEM, cathodoluminescence, micro-raman and photoluminescence.
1. N Harada, A Ferrier, D Serrano, M Persechino, E Briand, R Bachelet I. VIckridge, J. J. Ganem P. Goldner A. Tallaire “Chemically vapor deposited Eu3+:Y2O3 thin films as a material platform for quantum technologies” Journal of Applied Physics 128 (5), 055304 (2020)