Mobility enhancement of a high electron mobility transistor via external strain
Abstract
The effect of external strain in the growth of High-Electron Mobility Transistor was investigated. The layer was grown by Molecular Beam Epitaxy at elevated temperature (690°C). High resolution x-ray diffraction of the grown layer revealed that indium diffused into the Gallium Arsenide (GaAs) substrate. Hall measurements at 10K showed that there was an increase in the mobility due to strain. Reflectivity measurements at 10K of the As-grown layer showed the splitting of the heavy-hole (HH) – light-hole (LH) bands, indicating that the layer was strained. The separation was about 2.6meV at 10K and broadening of the PL peak in the 1.516eV was observed. The increase in mobility was attributed to change in the effective mass of the electron in the conduction band when the HH – LH bands were separated.