Improved Performance of AlGaN/GaN Heterojunction Field-Effect Transistors Using Delta Doping and a Binary Barrier

• Published in: Japanese Journal of Applied Physics Vol. 42; no. Part 2, No. 4A; pp. L353 - L355
• Main Authors: Wong, Michael M., Chowdhury, Uttiya, Sicault, Delphine, Becher, David T., Denyszyn, Jonathan C., Choi, Jin Ho, Zhu, Ting Gang, Feng, Milton, Dupuis, Russell D.
• Format: Journal Article
• Language: English
• Published: 01-04-2003
• ISSN: 0021-4922
• DOI: 10.1143/JJAP.42.L353

The improved performance of AlGaN/GaN heterojunction field-effect transistors using a delta-doping approach along with an AlN binary barrier is reported. Low-pressure MOCVD was used to grow the epitaxial heterostructures on semi-insulating SiC substrates. The maximum carrier mobility of mu =1,066 cm2/V-s and sheet carrier density of ns approximately equals 2.30 x 1013 cm-2 yields a large nsmu product of 2.45 x 1016 V-s. Devices with 0.15 mu m gate lengths exhibited a maximum current density of IDSmax=1.82 A/mm (at VG=+1 V) and a peak transconductance of gm=331 mS/mm. Furthermore, fT approximately equals 55 GHz and fmax approximately equals 115 GHz were measured. 7 refs.