Electrical characterization of Si-doped n-type α-Ga_2O_3 on sapphire substrates
Electrical characterization of Si-doped n-type α-Ga_2O_3 on sapphire substrates
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DOI：
10.1557/adv.2018.45
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发表时间：
2018-01
期刊：
影响因子：
0.8
通讯作者：
T. Uchida;K. Kaneko;S. Fujita
中科院分区：
文献类型：
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作者：
T. Uchida;K. Kaneko;S. Fujita
在雾状化学气相沉积α-Ga_2O_3过程中，Sn的掺杂问题主要是由于Sn的电离态由Sn^4+转变为Sn^2+和/或Sn在热退火后向外扩散，导致高阻薄膜的形成。而硅（Si）掺杂则通过使用新型掺杂源氯-（3-氰基丙基）-二甲基硅烷[ClSi（CH_3）_2（（CH_2）_2CN）]而成功。Si在α-Ga_2O_3薄膜中的掺入均匀，热退火后薄膜的电学性能稳定。作为供体的活化率接近100%。载流子（电子）浓度通过源溶液中的[Si]/[Ga]比控制在10^18 cm^-3的水平。最大迁移率为31.5 cm^2/V·s，而Sn掺杂为24 cm^2/V·s，表明Si掺杂的优势。但是，在蓝宝石衬底上异质外延生长的α-Ga_2O_3薄膜中位错缺陷的减少是下一步研究的重要课题。
Issues on tin (Sn) doping in the mist chemical vapor deposition of α-Ga_2O_3 was attributed to conversion of ionization states of Sn from Sn^4+ to Sn^2+ and/or out-diffusion of Sn after thermal annealing, resulting in highly resistive films. Silicon (Si) doping, instead, was succeeded by the use of a novel doping source of chloro-(3-cyanopropyl)-dimethylsilane [ClSi(CH_3)_2((CH_2)_2CN)]. Si was uniformly incorporated in the α-Ga_2O_3 films and the electrical properties were stable even after the thermal annealing. The activation ratio as donors was nearly 100%. The carrier (electron) concentration was controlled to the level of 10^18 cm^-3 by the [Si]/[Ga] ratio in the source solution. The maximum mobility was 31.5 cm^2/V⋅s, in contrast to 24 cm^2/V⋅s with Sn doping, suggesting advantage of Si doping . However, the reduction in dislocation defects in the α-Ga_2O_3 films formed owing to heteroepitaxy on sapphire was suggested to be the important subject to be considered in the next stage.