探究GSMBE制备GaAsBi薄膜中生长条件对Bi浓度的影响

发布时间：2018-05-06 19:46

  本文选题：GaAsBi + 气态源分子束外延　； 参考：《材料科学与工程学报》2017年03期

【摘要】：为了探究GaAsBi薄膜生长中生长条件与Bi浓度的关系,我们利用气态源分子束外延(GSMBE)技术,通过改变每个GaAsBi单层的生长温度、AsH_3压和Bi源温度,在半绝缘GaAs(100)衬底上生长GaAsBi的多层结构。通过二次离子质谱(SIMS)及透射电镜X光谱(EDX)测试得出:GaAsBi中Bi的浓度随着生长温度的升高而降低,且生长速率越慢表面偏析和再蒸发严重,可导致Bi浓度下降趋势更明显;Bi浓度随着AsH_3压的升高而减小,在As_2和Ga束流比在0.5~0.8之间几乎成线性变化,远不如固态源MBE敏感;此外,Bi源温度升高,Bi掺入的浓度也会增大,但是当生长温度大于420℃时,Bi就很难凝入。
[Abstract]:In order to investigate the relationship between the growth conditions and Bi concentration in the growth of GaAsBi thin films, we use the gas source molecular beam epitaxy (GMBE) technique. By changing the growth temperature of each GaAsBi monolayer, AsH3 voltage and Bi source temperature, we have grown the multilayer structure of GaAsBi on semi-insulating GaAs / Si (100) substrates. By means of secondary ion mass spectrometry (SIMS) and transmission electron microscopy (TEM) X-ray spectroscopy (EDX), it was found that the concentration of Bi in 1: GaAsBi decreases with the increase of growth temperature, and the slower the growth rate is, the more serious surface segregation and re-evaporation are observed. The decrease trend of Bi concentration is more obvious, and the concentration of Bi decreases with the increase of AsH_3 pressure. The ratio of As_2 to Ga beam is almost linearly changed between 0.5 and 0.8, which is far less sensitive than that of solid-state source MBE, and the concentration of Bi doping increases when the temperature of Bi source increases. However, when the growth temperature is higher than 420 鈩，

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