Enhancement of the Electrical Properties of AlGaN/GaN HFETs by Using Undoped Semi-Insulating GaN
- Resource Type
- Article
- Authors
- Y. H. Jeong; K. Y. Lim; C. S. Oh; E. H. Shin; J. W. Yang; J. Y. Kim
- Source
- Journal of the Korean Physical Society, 44(1), pp.140-143 Jan, 2004
- Subject
- 물리학
- Language
- ISSN
- 1976-8524
0374-4884
AlxGa1..xN/GaN heterostructure field effiect transistors (HFETs) have been fabricated on sapphire substrates (0001) by using low-pressure metalorganic chemical vapor deposition (LPMOCVD). These device structures require a semi-insulating GaN lm to enable drain-current pinch o. We have successfully grown the semi-insulating GaN without doping at high temperature and low pressure. The full width at half maximum (FWHM) of the X-ray diraction (XRD) rocking curve and the photoluminescence (PL) peak position for semi-insulating GaN were 441 arcsec and 38.5 meV, respectively. The root-mean-square (RMS) roughness of the semi-insulating GaN surface was 0.327 nm. The value of the specific resistivity was found to be 2.3 107 cm at 300 K. These results are due to complex effects, such as a reduction in the oxygen concentration and an increase in carrier trapping caused by dislocations. HFET based on the semi-insulating GaN with high resistivity enabled the drain current to pinch off.