Title :
Experimental and theoretical characteristics of high performance pseudomorphic double heterojunction InAlAs/In0.7Ga0.3 As/InAlAs HEMT´s
Author :
Kwon, Youngwoo ; Pavlidis, Dimitris ; Brock, Timothy L. ; Streit, Dwight C.
Author_Institution :
Dept. of Electr. Eng. & Comput. Sci., Michigan Univ., Ann Arbor, MI, USA
fDate :
6/1/1995 12:00:00 AM
Abstract :
Pseudomorphic double heterojunction (DH) InAlAs/In0.7Ga 0.3As/InAlAs HEMT´s with very high cut-off frequencies and current densities have been demonstrated. DC and microwave characteristics of the double heterojunction and single heterojunction (SB) HEMT´s have been compared. Two identical layers except for the dopings have been grown and fabricated using a conventional non-self-aligned process for this purpose. In order to further enhance the performance level of DH-HEMT´s, a sub-0.1 μm offset Γ-gate self-aligned process has been used on DH layers. A minimum frequency of oscillation (fmax) of 350 GHz and a current gain cut-off frequency (fT) of 180 GHz have been achieved in this way along with the full channel current of 1.2 A/mm. Theoretical simulation using 2-D ensemble Monte Carlo simulation has also been performed to optimize the DH layer structure and to study the transport characteristics of DB-HEMT´s compared with SH counterparts
Keywords :
III-V semiconductors; Monte Carlo methods; aluminium compounds; current density; electron beam lithography; gallium arsenide; indium compounds; microwave field effect transistors; microwave power transistors; millimetre wave field effect transistors; millimetre wave power transistors; power HEMT; power field effect transistors; semiconductor epitaxial layers; 0.1 micron; 180 GHz; 2D ensemble Monte Carlo simulation; 350 GHz; DC characteristics; EHF; InAlAs-In0.7Ga0.3As-InAlAs; MM-wave device; current densities; cutoff frequencies; double heterojunction HEMT; microwave characteristics; nonself-aligned process; offset Γ-gate self-aligned process; power HEMT; pseudomorphic HEMT; transport characteristics; Circuit simulation; Current density; Cutoff frequency; DH-HEMTs; Doping; Heterojunctions; Indium compounds; Millimeter wave integrated circuits; Millimeter wave transistors; Voltage;
Journal_Title :
Electron Devices, IEEE Transactions on
