Physical and electrical investigation of ohmic contacts to AlGaAs/GaAs heterostructures
Physical and electrical investigation of ohmic contacts to AlGaAs/GaAs heterostructures
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AlGaAs/GaAs 异质结构欧姆接触的物理和电气研究
DOI：
10.1063/1.357908
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发表时间：
1994
期刊：
影响因子：
--
通讯作者：
P. Marshall
中科院分区：
文献类型：
--
作者：
Richard Taylor;P. Coleridge;M. Davies;Y. Feng;J. McCaffrey;P. Marshall
研究了Ni-Au-Ge金属化在调制掺杂AlGaAs/GaAs异质结中与二维电子气(2DEG)建立电接触的机制。通过低温下的磁阻测量对样品进行了电学表征，并用透射电子显微镜对样品进行了检测。我们给出了一幅图像，其中在沉积的金属化下存在电子密度降低的二维电子气。接触过程的成功是根据这种密度的大小以及一系列金属尖峰的大小、面密度和穿透深度来描述的，这些尖峰建立了与2D EG的电连接。我们认为，电学行为不是由尖峰/2DEG界面的电流注入过程决定的，而是由尖峰形成的解毒剂阵列的散射和2DEG密度与金属垫大小的关系决定的。这张照片对未来的纳米结构器件、铁和稀土元素的研究具有重要的意义。
The mechanism by which Ni‐Au‐Ge metallizations establish electrical contact to the two‐dimensional electron gas (2DEG) in modulation‐doped AlGaAs/GaAs heterostructures is investigated. Transmission electron microscopy was used to examine samples after electrical characterization by magnetoresistance measurements at cryogenic temperatures. We present a picture in which a 2DEG of reduced electron density exists under the deposited metallization. The success of the contacting procedure is described in terms of the magnitude of this density and the size, areal density, and penetration depth of a series of metallic spikes which establish the electrical link to the 2DEG. We suggest that the electrical behavior is not dominated by the current injection process at the spike/2DEG interface but is instead dictated by scattering from the array of antidots formed by the spikes and by a dependence of the 2DEG density on the size of the metallic pad. The implications of this picture for future nanostructure devices, fe...