Title :
Ring oscillator using InAlAs/InGaAs/InP enhancement/depletion-mode high electron mobility transistor direct-coupled FET logic inverters
Author :
Cueva, G. ; Mahajan, A. ; Fay, P. ; Arafa, M. ; Adesida, I.
Author_Institution :
Coordinated Sci. Lab., Illinois Univ., Urbana, IL, USA
Abstract :
The authors report the fabrication and characterization of E/D-mode 0.5 μm gate-length direct-coupled FET logic (DCFL) inverters, and an 11-stage ring oscillator with a 3-stage output buffer, based on these inverters. Testing of discrete 0.5 μm devices gave threshold voltages of 195 mV with a standard deviation of 9 mV for the E-HEMTs, and -365 mV with a standard deviation of 19 mV for the D-HEMTs. RF testing yields unity current gain cutoff frequencies (ft) of 70 GHz and 67 GHz for the E-HEMTs and D-HEMTs respectively. The inverters were tested for DC performance and the voltage transfer curve shows noise margins of 145 mV at supply voltages as low as 0.6 V. The ring oscillator was tested using a spectrum analyzer and shows propagation delays as low as 20.66 ps/stage, power dissipation as low as 120 μW/stage, and power delay products as low as 2.65 fJ/stage. The fabrication process, inverters, and ring oscillator are described in detail
Keywords :
HEMT integrated circuits; III-V semiconductors; aluminium compounds; direct coupled FET logic; field effect logic circuits; gallium arsenide; high electron mobility transistors; indium compounds; integrated circuit technology; logic gates; millimetre wave field effect transistors; -365 mV; 0.5 mum; 11-stage ring oscillator; 195 mV; 20.66 ps; 3-stage output buffer; 67 GHz; 70 GHz; D-HEMTs; DC performance; E-HEMTs; E/D-mode; InAlAs-InGaAs-InP; InAlAs/InGaAs/InP enhancement/depletion-mode HEMT DCFL inverters; InP; RF testing; direct-coupled FET logic; discrete device testing; fabrication process; noise margins; power delay products; power dissipation; propagation delays; spectrum analyzer; threshold voltage; unity current gain cutoff frequencies; voltage transfer curve; FETs; Fabrication; Indium compounds; Indium gallium arsenide; Indium phosphide; Inverters; Propagation delay; Ring oscillators; Testing; Voltage-controlled oscillators;
Conference_Titel :
Indium Phosphide and Related Materials, 1997., International Conference on
Conference_Location :
Cape Cod, MA
Print_ISBN :
0-7803-3898-7
DOI :
10.1109/ICIPRM.1997.600078