Regensburg 2019 – wissenschaftliches Programm
HL 45.57: Poster
Donnerstag, 4. April 2019, 18:30–21:00, Poster E
Characterization of κ-(Al,Ga)2O3 Thin Films grown by VCCS PLD — •P. Storm, M. Kneiss, D. Splith, H. von Wenckstern, M. Lorenz, and M. Grundmann — Universität Leipzig, Felix-Bloch Institut für Festkörperphysik
Ga2O3 is a wide band gap semiconductor with Eg=4.4−5.3 eV depending on the respective polymorph . Compared to the monoclinic β-phase, the orthorhombic κ-phase exhibits promising features like ferroelectic properties with high spontaneous polarization, possibly leading to the formation of 2DEGs with high electron densities at heterointerfaces. Alloying with Al allows band gap engineering, which is substantial for optoelectronic devices utilizing heterostructures, such as quantum well infrared photodetectors or modulation doped FETs and has therefore been investigated in this study. To achieve this, VCCS-PLD, a novel PLD method allowing the realization of vertical continuous composition spread (VCCS), has been utilized . It enables direct control of the particle flux composition in the PLD plasma and the corresponding thin film compositions using a single radially-segmented target. Employing this technique, we have grown (Al,Ga)2O3 thin films (on c-sapphire substrates and MgO(111) buffer layers) with varying flux of tin in the PLD plasma to determine the critical content of this catalyst for κ-phase growth. Using the same technique, we varied the Al-content to investigate the structural and morphological impacts of Al in κ-phase Ga2O3.
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