MBE生长碲镉汞的砷掺入与激活

发布时间：2018-03-03 22:08

  本文选题：红外焦平面　切入点：碲镉汞　出处：《红外与毫米波学报》2017年05期 　论文类型：期刊论文

【摘要】：采用As掺杂和激活技术制备的p+-on-n异质结材料是获得高性能长波碲镉汞红外焦平面器件的关键技术之一,得到了广泛关注.采用变温IV拟合的方法,对不同As掺入浓度与器件结性能相关性进行了分析,发现降低结区内As掺杂浓度可以有效抑制器件的陷阱辅助隧穿电流.拟合结果表明,较高浓度的Nt很可能与高浓度As掺入相关.因此As的稳定均匀掺入和激活被认为是主要技术挑战.实验研究了分子束外延过程中Hg/Te束流比与As掺入效率的关系,发现相对富Hg的外延条件有助于提高As掺杂效率.研究还发现As的晶圆内掺杂均匀性与Hg/Te束流比的均匀性密切相关.对As的激活退火进行了研究,发现在饱和Hg蒸汽压中采用300℃/16h+420℃/1 h+240℃/48 h的退火条件能明显提升碲镉汞中As原子的激活率.
[Abstract]:P-on-n heterojunction materials fabricated by as doping and activation techniques are one of the key technologies for obtaining high performance long-wave mercury cadmium telluride infrared focal plane devices. The correlation between as doping concentration and device junction performance is analyzed. It is found that decreasing as doping concentration in junction region can effectively suppress the trap assisted tunneling current of the device. Therefore, the stable and uniform incorporation and activation of as is considered to be a major technical challenge. The relationship between Hg/Te beam ratio and as incorporation efficiency in molecular beam epitaxy (MBE) is investigated experimentally. It is found that the epitaxial conditions with relatively rich Hg contribute to the improvement of as doping efficiency. It is also found that the homogeneity of doping in as wafer is closely related to the uniformity of Hg/Te beam ratio. The activation annealing of as is studied. It is found that the activation rate of as atoms in Hg tellurium can be significantly increased by annealing at 300 鈩，

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