In:Ga_2O_3氧化物半导体晶体的生长与性能研究

Growth and Property of In:Ga_2O_3 Oxide Semiconductor Single Crystal

β-Ga_2O_3晶体是一种新型宽禁带氧化物半导体材料,本征导电性差。为了在调控导电性能的同时兼顾高的透过率和结晶性能,离子掺杂是一种有效的途径。采用光学浮区法生长出f8 mm×50 mm蓝色透明In:Ga_2O_3晶体,晶体具有较高的结晶完整性。In^(3+)离子掺杂后,β-Ga_2O_3晶体在红外波段出现明显的自由载流子吸收,热导率稍有减小。室温下,In:Ga_2O_3晶体的电导率和载流子浓度分别为4.94×10^(-4)S/cm和1.005×1016 cm^(-3),其值高于β-Ga_2O_3晶体约1个数量级。In:Ga_2O_3晶体电学性能对热处理敏感,1200℃空气气氛和氩气气氛退火后电导率降低。结果表明,In^(3+)离子掺杂能够调控β-Ga_2O_3晶体的导电性能。

β-Ga203 crystal is a novel oxide semiconductor with wide bandgap, but its intrinsic conductive capabil- ity is poor. Ion doping is an effective way to regulate conductivity, transparency and crystallinity of the crystal. Transparent blue In：Ga203 single crystal with the dimension of Ф8 mm×50 mm was grown by optical floating zone method. The as-grown crystal is of good crystallization quality. After doping In^3＋ ion, 13-Ga2Oa crystal has strong in- frared absorption, and its thermal conductivity slightly decreases. At room temperature, the electrical conductivity and carrier concentration of as-grown In：Ga203 crystal are 4.94×10^-4 S/cm and 1.005×10^16 cm^-3, respectively, which are approximately one order magnitude higher than that of undoped β-Ga203 crystal. The electrical property of In：Ga203 crystal is sensitive to heat treatment. After annealing at 1200℃ in air or in argon, its electrical conductiv- ity decreases. These experimental results suggest that In^3＋ ion doping can improve the electrical property of β-Ga203 single crystal.