Title :
Metamorphic HFETs with composite In0.8Ga0.2As/InAs/In0.8Ga0.2 As channels on GaAs substrate
Author :
Karlsson, Christer ; Rorsman, Niklas ; Wang, Shumin ; Persson, Magnus
Author_Institution :
Dept. of Microwave Technol., Chalmers Univ. of Technol., Goteborg, Sweden
Abstract :
Metamorphic HFET materials with InAs/In0.8Ga0.2 As channels have been grown on GaAs substrates. The influence of the insertion of an InAs layer has been investigated regarding the thickness and the position of the layer. The insertion of InAs results in 20% increase in electron mobility at room temperature (34% at 77 K). HFETs with 0.3 μm gate length have been fabricated and characterized. An extrinsic DC transconductance of 1100 mS/mm was achieved. Excellent high frequency performance has been achieved at low voltages. An fmax of 100 GHz and an fτ of 100 GHz were achieved at a drain voltage of 0.25 V and 0.75 V respectively. The fτ.lg product of 30 GHz-μm corresponds to a carrier velocity of 1.9.107 cm/s. The minimum noise figure was 0.8 dB with an associated gain of 9.2 dB at 25 GHz
Keywords :
III-V semiconductors; electron mobility; gallium arsenide; indium compounds; junction gate field effect transistors; semiconductor device noise; 1100 mS; 25 GHz; 77 K; GaAs; GaAs substrate; In0.8-Ga0.2As-InAs-In0.8Ga 0.2As; carrier velocity; drain voltage; electron mobility; extrinsic DC transconductance; high frequency performance; metamorphic HFET; minimum noise figure; Electron mobility; Frequency; Gain; Gallium arsenide; HEMTs; Low voltage; MODFETs; Noise figure; Temperature; Transconductance;
Conference_Titel :
Compound Semiconductors, 1997 IEEE International Symposium on
Conference_Location :
San Diego, CA
Print_ISBN :
0-7503-0556-8
DOI :
10.1109/ISCS.1998.711720
