Presentation Information
[10p-N105-6]Fabrication of (100) Thin Film β-Ga2O3 on Insulator towards Optical Applications
〇(P)Natthajuks Pholsen1, Jewook Jeon2, Hideo Otsuki1, Takayoshi Oshima3, Riena Jinno2, Satoshi Iwamoto1,2 (1.IIS, UTokyo, 2.RCAST, UTokyo, 3.NIMS)
Keywords:
gallium oxide,wide bandgap semiconductor
Ga2O3 holds promise for a wide range of photonic applications, including UV waveguiding, nonlinear optics, broadband luminescence, and quantum photonics with color centers. The realization of these applications, especially quantum photonics, depends on the availability of high-quality, single-crystalline Ga2O3 integrated on a low-index insulative layer to enable optical confinement and electrical isolation, similar to the silicon-on-insulator (SOI) platform widely used in silicon photonics. Here, we propose a method to fabricate (100) thin film β-Ga2O3 on a SiO2 substrate for optical applications. β-Ga2O3 on a SiO2 can be fabricated by bonding and peeling. (100) plane of β-Ga2O3 is a cleavage plane, and the crystal can be peeled along this plane. We first bond cleaved β-Ga2O3 crystal with (100) surfaces on two SiO2 substrates with benzocyclobutene (BCB), spin-coated on the surface of SiO2. The surfaces of the gallium oxide crystal are peeled when the glass substrates are separated. We could not control the thickness of the film yet, but the process can be repeated until several tens of microns of film remain. An AFM measurement reveals the local surface roughness (RMS) of a peeled flim to be 0.06 nm. We will investigate thinning down with reactive ion etching (RIE) and report the details at the conference.