Influence of a carrier supply layer on carrier density and drift mobility of AlGaN/GaN/SiC high-electron-mobility transistors
English
Marso, Michel[University of Luxembourg > Faculty of Science, Technology and Communication (FSTC) > Engineering Research Unit > ; Institute of Thin Films and Interfaces (ISG1) and cni - Center of Nanoelectronic Systems for Information Technology, Research Centre Jülich, 52425 Jülich, Germany]
Bernát, J.[Institute of Thin Films and Interfaces (ISG1) and cni - Center of Nanoelectronic Systems for Information Technology, Research Centre Jülich, 52425 Jülich, Germany]
Javorka, P.[Institute of Thin Films and Interfaces (ISG1) and cni - Center of Nanoelectronic Systems for Information Technology, Research Centre Jülich, 52425 Jülich, Germany]
Kordoš, P.[Institute of Thin Films and Interfaces (ISG1) and cni - Center of Nanoelectronic Systems for Information Technology, Research Centre Jülich, 52425 Jülich, Germany]
[en] Sheet carrier concentration and low-field drift mobility of intentionally undoped and modulation-doped AlGaN/GaN heterostructures on SiC substrate were evaluated by capacitance-voltage and channel conductivity measurements. Sheet carrier concentration and average mobility at 0 V gate bias correspond to standard Hall results. Sheet carrier density increases from 6.831012 cm22 for the undoped sample up to 131013 cm22 for the device with the highest doping concentration, while the mobility decreases from 1800 to 1620 cm2/V s. The local mobility, on the other hand, depends only on the actual sheet carrier density and is not influenced by the doping concentration of the carrier supply layer. It reaches a maximum value of 2100 cm2/Vs at a carrier density of 331012 cm22.