Degenerate layers in epitaxial ZnO films grown on sapphire substrates
Degenerate layers in epitaxial ZnO films grown on sapphire substrates
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DOI：
10.1063/1.1758295
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发表时间：
2004-05
影响因子：
4
通讯作者：
H. Tampo;A. Yamada;P. Fons;H. Shibata;K. Matsubara;K. Iwata;S. Niki;K. Nakahara;H. Takasu
中科院分区：
文献类型：
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作者：
H. Tampo;A. Yamada;P. Fons;H. Shibata;K. Matsubara;K. Iwata;S. Niki;K. Nakahara;H. Takasu
采用自由基源分子束外延技术在蓝宝石a面（11-20）衬底上低温缓冲层上生长ZnO薄膜。LT缓冲层被发现影响随后生长的未掺杂的ZnO薄膜的电性能，并且它们的存在被发现是不可缺少的低载流子浓度和高迁移率的薄膜的生长。随温度变化的霍尔测量结果表明，存在一个退化的区域相关的LT缓冲层。结果表明，通过退火处理和氮掺杂可以减小退化层的影响。110毫电子伏的占主导地位的剩余施主能量被发现是不同于以前报道的。使用氮掺杂缓冲层制造的ZnO膜的载流子浓度为7.5×1016 cm-3，室温下的迁移率为132 cm 2/V s。
ZnO films were grown on low-temperature (LT) buffer layers on sapphire a-plane (11–20) substrates by radical source molecular-beam epitaxy. The LT buffer layers were found to effect the electrical properties of subsequently grown undoped ZnO films, and their presence was found to be indispensable for the growth of films with low carrier concentrations and high mobilities. Temperature-dependent Hall measurements showed the existence of a degenerate region related to the LT buffer layers. It was found that the effects of degenerate layers could be reduced by using annealing treatments and nitrogen doping of the LT buffer layers. The dominant residual donor energy of 110 meV was found to be different than previously reported. The carrier concentration of a ZnO film fabricated using a nitrogen-doped buffer layer was 7.5×1016 cm−3 with a mobility of 132 cm2/V s at room temperature.