Physics of GaN High Electron Mobility Transistors

摘要

The nitride High Electron Mobility (HEMTs) have a great potential for high power and RF applications because of a high breakdown field, a very large density of the polarization induced two-dimensional electrons, high electron velocities and mobilities, excellent thermal properties, chemical inertness, and radiation hardness. GaN power transistors grown on silicon substrates are already being commercialized. However, the full potential of the nitride based HEMTs is still to be achieved and will require improvements in the device design that account for the both materials properties and device physics of wide band gap transistors. Such new features include the diamond substrates for a better heat removal, adding a low conducting passivation between the gate and drain, using the perforated channel with perforations extending beyond the gate, implementing the HEMT technology in the AlInN/GaN materials system for lattice matching design and employing lateral-vertical designs for a higher breakdown voltage.