Origin of gate hysteresis in p-type Si-doped AlGaAs/GaAs heterostructures

Article

关键词: LEVEL TRANSIENT SPECTROSCOPY;    ELECTRONIC-PROPERTIES;    SULFIDE PASSIVATION;    HEAVILY SI;    GAAS;    CONDUCTANCE;    ORIENTATION;    ABSORPTION;    TRANSISTOR;    SCATTERING;   

DOI  :  10.1103/PhysRevB.86.165309

来源: SCIE

【 摘 要 】

Gate instability/hysteresis in modulation-doped p-type AlGaAs/GaAs heterostructures impedes the development of nanoscale hole devices, which are of interest for topics from quantum computing to novel spin physics. We present an extended study conducted using custom-grown, matched modulation-doped n-type and p-type heterostructures, with and without insulated gates, aimed at understanding the origin of the hysteresis. We show the hysteresis is not due to the inherent leakiness of gates on p-type heterostructures, as commonly believed. Instead, hysteresis arises from a combination of GaAs surface-state trapping and charge migration in the doping layer. Our results provide insights into the physics of Si acceptors in AlGaAs/GaAs heterostructures, including widely debated acceptor complexes such as Si-X. We propose methods for mitigating the gate hysteresis, including poisoning the modulation-doping layer with deep-trapping centers (e.g., by codoping with transition metal species) and replacing the Schottky gates with degenerately doped semiconductor gates to screen the conducting channel from GaAs surface states.

【 授权许可】

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