ZnO Heteroepitaxy on Sapphire Using a Novel Buffer Layer of Titanium Oxide: Crystallographic Behavior

• 作者: Satoshi Yamauchi Yoh Imai
• 来源期刊: 晶体结构理论与应用(英文)
• 学科: 物理学
• 关键词: ZNO Ti2O3 Plasma-Assisted EPITAXY Hexagonal PYRAMID Grain
• 年，卷（期）: 2013,（2）
• 页码范围: 39-45
• 页数: 7页
• 分类号: O48

摘要

A novel buffer layer consists of titanium oxide grown on a-sapphire by low-pressure chemical vapor deposition using titanum-tetra-iso-propoxide and oxygen gas was used for ZnO epitaxial growth at temperature as low as 340℃ by plasma-assisted epitaxy using radio-frequency oxygen-gas plasma. XRD and RHEED indicated (0001)Ti2O3 layer in corundum crystal system was epitaxially grown on the substrate in an in-plane relationship of [1-100]Ti2O3// [0001]Al2O3 by uniaxial phase-lock system. Growth behavior of ZnO layer was significantly dependent on the Ti2O3 buffer-layer thickness, for example, dense columnar ZnO-grains were grown on the buffer layer thinner than 10 nm but the hexagonal pyramid-like grains were formed on the thin buffer layers below 2 nm. RHEED observations showed ZnO layer including the pyramid-like grains was epitaxially grown with single-domain on the thin buffer layer of 0.8 nm in the in-plane relationship of [1-100]ZnO//[1-100]Ti2O3//[0001]Al2O3, whereas the multi-domain was included in ZnO layer on the buffer layer above 10 nm.