Fabrication and performance of GaN electronic devices

S.J. Pearton, F. Ren, A.P. Zhang, K.P. Lee
2000 Materials science & engineering. R, Reports  
GaN and related materials (especially AlGaN) have recently attracted a lot of interest for applications in high power electronics capable of operation at elevated temperatures. Although the growth and processing technology for SiC, the other viable wide bandgap semiconductor material, is more mature, the AlGaInN system offers numerous advantages. These include wider bandgaps, good transport properties, the availability of heterostructures (particularly AlGaN/GaN), the experience base gained by
more » ... he commercialization of GaN-based laser and lightemitting diodes and the existence of a high growth rate epitaxial method (hydride vapor phase epitaxy) for producing very thick layers or even quasi-substrates. These attributes have led to rapid progress in the realization of a broad range of GaN electronic devices, including heterostructure field effect transistors (HFETs), Schottky and p±i±n rectifiers, heterojunction bipolar transistors (HBTs), bipolar junction transistors (BJTs) and metal-oxide semiconductor field effect transistors (MOSFETs). This review focuses on the development of fabrication processes for these devices and the current state-of-the-art in device performance, for all of these structures. We also detail areas where more work is needed, such as reducing defect densities and purity of epitaxial layers, the need for substrates and improved oxides and insulators, improved p-type doping and contacts and an understanding of the basic growth mechanisms. # The strongest feature of the III±V nitrides compared to SiC is the heterostructure technology it can support. Quantum well, modulation-doped heterointerface, and heterojunction structure can all be made in this system, giving access to new spectral regions for optical devices and new operation regimes for electronic devices. From this point of view, III±V nitrides can be considered the wide band gap equivalent of the AlGaAs/InGaAs system which has set the modern benchmark for microwave device performance. Other attractive properties of III±V nitrides include high mechanical and thermal stability, large piezoelectric constants and the possibility of passivation by forming thin layers of Ga 2 O 3 or Al 2 O 3 with band gaps of 4.3 and 9.2 eV, respectively. In addition, AlN has received considerable attention for its insulating property [5], particularly as a potential isoelectronic insulator for GaAs field effect transistors (FETs).
doi:10.1016/s0927-796x(00)00028-0 fatcat:ev54z37k2bdjvfwdfrtpnfsunq