Title :
Delta-doped AlGaN/AlN/GaN microwave HFETs grown by metalorganic chemical vapour deposition
Author :
Wong, M.M. ; Chowdhury, U. ; Sicault, D. ; Becher, D.T. ; Denyszyn, J.C. ; Zhu, T.G. ; Feng, M. ; Dupuis, R.D.
Author_Institution :
Microelectron. Res. Center, Texas Univ., Austin, TX, USA
fDate :
4/25/2002 12:00:00 AM
Abstract :
The performance of an innovative delta-doped AlGaN/AlN/GaN heterojunction field-effect transistor (HFET) structure is reported. The epitaxial heterostructures were grown on semi-insulating SiC substrates by low-pressure metalorganic chemical vapour deposition. These structures exhibit a maximum carrier mobility of 1058 cm2/V s and a sheet carrier density of 2.35×1013 cm-2 at room temperature, corresponding to a large ns μn product of 2.49×1016 V s. HFET devices with 0.25 μm gate length were fabricated and exhibited a maximum current density as high as 1.5 A/mm (at VG=+1 V) and a peak transconductance of gm=240 mS/mm. High-frequency device measurements yielded a cutoff frequency of ft≃50 GHz and maximum oscillation frequency fmax≃130 GHz
Keywords :
III-V semiconductors; MOCVD; aluminium compounds; carrier mobility; current density; doping profiles; gallium compounds; microwave field effect transistors; microwave power transistors; power field effect transistors; vapour phase epitaxial growth; wide band gap semiconductors; 0.25 micron; 130 GHz; 240 mS/mm; 50 GHz; AlGaN delta-doped charge layer; AlGaN-AlN-GaN; SiC; TDEG; binary AIN barrier; carrier mobility; delta-doped HFET structure; epitaxial heterostructures; heterojunction FET structure; heterojunction field-effect transistor; high-power HFET; low-pressure MOCVD; metalorganic CVD; metalorganic chemical vapour deposition; microwave HFETs; semi-insulating SiC substrates; sheet carrier density; two-dimensional electron gas;
Journal_Title :
Electronics Letters
DOI :
10.1049/el:20020247
