화학공학소재연구정보센터
Journal of Crystal Growth, Vol.247, No.3-4, 509-515, 2003
Heteroepitakial oxide structures grown by pulsed organometallic beam epitaxy (POMBE)
We describe the design, construction, and use of pulsed organometallic beam epitaxy (POMBE), a plasma-enhanced CVD technique to grow oxide heterostructures. Solid-state precursors are sampled in the gas line via quartz crystal monitors and injected into the O-2 microwave plasma with pulse time durations of a few seconds. The precursors are injected through pneumatic valves in a heated valve box. The valves and microwave power are under computer control. The microwave plasma is ramped between a forward power of 600 and 1500 W to improve film epitaxy. We use POMBE to grow epitaxial BaYZrO3/MgO, Y-ZrO2/LAO, and YBa2Cu3O7/Y-ZrO2/LAO structures. The processing parameters leading to the heteroepitaxy are described. The best epitaxy results in X-ray FWHM of 0.12degrees, 0.38degrees, and 0.87degrees for BaYZrO3, Y-ZrO2, and YBa2Cu3O7, respectively. We show the advantages of the POMBE technique over that of plasma-enhanced CVD. Selected TEM results of the heteroepitaxial oxide structures are shown, and the role that temperature plays in the oxide epitaxy. The epitaxy of BaYZrO3 is the first described in the literature, and that of YSZ is among the best reported. (C) 2002 Elsevier Science B.V. All rights reserved.