Observation and control of the amphoteric behaviour of Si-doped InSb grown on GaAs by MBE
Observation and control of the amphoteric behaviour of Si-doped InSb grown on GaAs by MBE
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MBE 生长在 GaAs 上的硅掺杂 InSb 两性行为的观察和控制
DOI：
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发表时间：
1989
期刊：
影响因子：
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通讯作者：
D. W. Pashley
中科院分区：
文献类型：
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作者：
S. Parker;R. Williams;R. Droopad;R. Stradling;K. Barnham;S. Holmes;J. Laverty;C. Phillips;E. Skuras;R. H. Thomas;X. Zhang;A. Staton;D. W. Pashley
本文研究了GaAs（100）衬底上InSb异质外延层的MBE生长和掺杂。通过低场霍尔和磁阻测量以及高场Shubnikov-de哈斯研究以及红外透射和TEM来评估层。硅掺入的机制作为生长温度的函数进行了研究。在低生长温度（约=340摄氏度）下，硅仅作为施主，并且可以产生高达3*1018 cm-3的电子浓度，具有与块体材料相同的77 K迁移率。虽然可以达到高于3*1018 cm-3的浓度，但在这些样品中似乎发生了自动补偿。77 K迁移率达到较低的重掺杂样品（>40000 cm 2 V-1 s-1，n=1.2*1017 cm-3的样品在340 ℃下生长）是最高的低温迁移率尚未报道的n型InSb薄膜约=1 μ m厚的GaAs上生长。然而，较高的生长温度（约=420摄氏度）结合恒定的硅通量被发现，同时降低电子浓度和迁移率在77 K测量，虽然通过TEM评估的结构质量保持不变。分析所观察到的行为方面的Brooks-Herring模型的电离杂质散射，修改为nonparabolicity，表明硅是acetterically与补偿比（NA/ND）达到0.5在较高的温度下。GaAs和InSb之间的界面（晶格失配=14%）的电性能的影响进行了研究，通过引入掺杂板的厚度约=1300 AA在不同的距离（d）之间的界面（d=0 μ m）和表面（d约=1.5 μ m）的外延层。一系列的峰不周期性的倒易场（1/B）被发现在低场与B平行的板片，并解释为所产生的大量的子带占据的结果，相当厚的板片的抗磁性人口减少。Be掺杂在2*1019 cm-3被证明，与硅一样，实现了对应于该空穴浓度的体迁移率。
The MBE growth and doping of heteroepitaxial layers of InSb on GaAs (100) are investigated. The layers are assessed by low-field Hall and magnetoresistivity measurements and high-field Shubnikov-de Haas studies together with infrared transmission, and TEM. The mechanism for silicon incorporation is investigated as a function of growth temperature. At low growth temperatures ( approximately=340 degrees C) silicon acts only as a donor and can produce electron concentrations up to 3*1018 cm-3 with 77 K mobilities identical to those found with bulk material. Although higher concentrations than 3*1018 cm-3 can be achieved; auto-compensation appears to occur in those samples. The 77 K mobilities achieved for less heavily doped samples (>40000 cm2 V-1 s-1 for n=1.2*1017 cm-3 for samples grown at 340 degrees C) are the highest low-temperature mobilities yet reported for n-type InSb films of approximately=1 mu m thickness grown on GaAs. However, higher growth temperatures ( approximately=420 degrees C) combined with constant silicon flux are found to simultaneously decrease electron concentration and mobility measured at 77 K although the structural quality as assessed by TEM remains unchanged. Analysis of the observed behaviour in terms of the Brooks-Herring model of ionised impurity scattering, modified for nonparabolicity, suggests that silicon is acting amphoterically with compensation ratios (NA/ND) reaching 0.5 at the higher temperatures. The effect of the interface between GaAs and InSb (lattice mismatch=14%) on the electrical properties is studied by introducing doping slabs of thickness approximately=1300 AA at various distances (d) between the interface (d=0 mu m) and the surface (d approximately=1.5 mu m) of the epilayer. A series of peaks not periodic in reciprocal field (1/B) are found at low fields with B parallel to the slabs and are interpreted as arising from the diamagnetic depopulation of the large number of subbands occupied as a result of the considerable thickness of the slabs. Be doping at 2*1019 cm-3 was demonstrated and, as with silicon, the bulk mobility corresponding to this hole concentration was achieved.