Lateral variations in threshold voltage of an AlxGa1ÀxNÕGaN heterostructure field-effect transistor measured by scanning capacitance spectroscopy
نویسندگان
چکیده
Local dC/dV spectroscopy performed in a scanning capacitance microscope ~SCM! was used to map, quantitatively and with high spatial resolution (;50 nm), lateral variations in the threshold voltage of an AlxGa12xN/GaN heterostructure field-effect transistor epitaxial layer structure. Scanning capacitance and the associated threshold voltage images show small round features less than 150 nm in diameter with a corresponding shift in threshold voltage of about 1.5–2 V, and larger features several microns in size with a corresponding shift in threshold voltage of approximately 1 V. The small features in the SCM and threshold voltage images are consistent with the presence of charged threading dislocations, while the variations in threshold voltage over large areas could be a result of thickness and/or composition variations in the AlxGa12xN layer. © 2001 American Institute of Physics. @DOI: 10.1063/1.1335840#
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Quantitative analysis of nanoscale electronic properties in an AlxGa1ÀxNÕGaN heterostructure field-effect transistor structure
Local dC/dV spectroscopy performed in a scanning capacitance microscope is used to map, quantitatively and with high spatial resolution, lateral variations in the threshold voltage of an AlxGa12xN/GaN heterostructure field-effect transistor epitaxial layer structure. Theoretical analysis and numerical simulations are used to quantify charge concentrations, the corresponding threshold voltage sh...
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