Formation Mechanism of CuAlO₂ Prepared by Rapid Thermal Annealing of Al₂O₃/Cu₂O/Sapphire Sandwich Structure

详细信息	查看全文 | 推荐本文 |

• 作者：C.H. Shih ; B.H. Tseng ; ^{baeheng@mail.nsysu.edu.tw}
• 关键词：oxide semiconductors ; thin film reaction ; rapid thermal annealing
• 刊名：Physics Procedia
• 出版年：2012
• 期刊代码：P128_18753892
• 类别：ph
• 出版时间：2012
• 卷：32
• 期：Complete
• 页码：395-400
• 文件大小：1489 K

摘要

Single-phase CuAlO₂ films were successfully prepared by thin-film reaction of an Al₂O₃/Cu₂O/sapphire sandwich structure. We found that the processing parameters, such as heating rate, holding temperature and annealing ambient, were all crucial to form CuAlO₂ without second phases. Thermal annealing in pure oxygen ambient with a lower temperature ramp rate might result in the formation of CuAl₂O₄ in addition to CuAlO₂, since part of Cu₂O was oxidized to form CuO and caused the change in reaction path, i.e. CuO + Al₂O₃ 鈫?#xA0;CuAl₂O₄. Typical annealing conditions successful to prepare single-phase CuAlO₂ would be to heat the sample with a temperature rampt rate higher than 7.3 掳C/sec and hold the temperature at 1100 掳C in air ambient. The formation mechanism of CuAlO₂ has also been studied by interrupting the reaction after a short period of annealing. TEM observations showed that the top Al₂O₃ layer with amorphous structure reacted immediately with Cu₂O to form CuAlO₂ in the early stage and then the remaining Cu₂O reacted with the sapphire substrate.