We present a process for creating in-plane anisotropic strain in (100) GaAs and GaAs/AlGaAs multiple quantum well (MQW) thin films. The host substrates used for bonding include (100) GaAs, (100) silicon, and lithium tantalate (LiTaO 3 ) with a special crystalline orientation. A multilyer metallization consisting of Au-Sn (Au: 80 wt%, Sn: 20 wt%, 0.95μm), Ti (500angstrom) adhesion layer and Pt (500angstrom) barrier layer is deposited on the thin films and the host substrates. By choosing a proper annealing temperature (380°C) and thickness of eutectic layer, the thin films and the substrates are bonded together. Photoluminescence measurements do not reveal any thermally induced strain in the thin films bonded to GaAs; however, they show the existence of in-plane biaxial strain in the films bonded on Si. Linearly polarized reflectance measurements reveal an optical anisotropy in the MQW bonded to LiTaO 3 , which possesses an orientation-dependent thermal expansion. This indicates that the in-plane strain in the thin films is induced by the different thermal expansions between the thin films and the substrates. This process can be used to develop a new class of devices with an artificially induced in-plane strain.
|Number of pages||6|
|Journal||Materials Research Society Symposium - Proceedings|
|State||Published - 1 Dec 1994|
|Event||Proceedings of the 1994 MRS Spring Meeting - San Francisco, CA, USA|
Duration: 4 Apr 1994 → 8 Apr 1994