Title :
Utilization of an electron beam resist process to examine the effects of asymmetric gate recess on the device characteristics of AlGaAs/InGaAs PHEMTs
Author :
Grundbacher, Ronald ; Ballegeer, Dan ; Ketterson, Andrew A. ; Kao, Y.C. ; Adesida, Ilesanmi
Author_Institution :
Dept. of Electr. & Comput. Eng., Illinois Univ., Urbana, IL, USA
fDate :
12/1/1997 12:00:00 AM
Abstract :
The DC and microwave characteristics of two sets of AlGaAs/InGaAs PHEMTs having a gate length of 0.2 μm are compared. The first set is composed of devices fabricated using a trilayer electron beam resist process for T-gate recess and metallization. The second set is composed of devices fabricated using a new four-layer electron beam resist process which enables the asymmetric placement of a T-gate in a wide recess trench. Devices fabricated using the four-layer resist process showed improved breakdown voltage, lower gate-drain feedback capacitance, lower output conductance, and higher fmax with only slight reduction of drain current and transconductance. For example, the off-state drain-source breakdown voltage increased from 5.2 to 12.5 V, and the fmax, increased from 133 to 158 GHz as the drain side cap recess, Lud, was increased from 0 to 0.55 μm
Keywords :
III-V semiconductors; aluminium compounds; capacitance; characteristics measurement; electron resists; gallium arsenide; high electron mobility transistors; indium compounds; microwave field effect transistors; millimetre wave field effect transistors; 0 to 0.55 micron; 133 to 158 GHz; 5.2 to 12.5 V; AlGaAs-InGaAs; DC characteristics; III-V semiconductors; PHEMTs; T-gate recess; asymmetric gate recess; breakdown voltage; drain current; drain side cap recess; four-layer electron beam resist; gate length; gate-drain feedback capacitance; microwave characteristics; output conductance; recess trench; transconductance; Electron beams; Fabrication; Indium gallium arsenide; Instruments; Laboratories; Lithography; Metallization; Microelectronics; Microwave devices; Resists;
Journal_Title :
Electron Devices, IEEE Transactions on
