Device Characteristics of Dry Etched AlGaAs/InGaAs HEMTs Fabricated by Inductively Coupled Plasma Etching

Jin-Hee Lee, Hyung-Sup Yoon, Chul-Wook Lee, Sang-Soo Choi, Sung-Jae Maeng, Kyung Ho Lee, Andrew Goodyear
Micro-Electronics Technology Laboratory, Electronics and Telecommunications Research Institute
Yusong, P.O.Box 106, Taejon, Korea

Passivated 0.2 mm pseudomorphic HEMTs (PHEMTs) were fabricated by combining a wide head T-shaped gate, formed by using a dose split method of electron beam lithography, with a short source-gate separation, formed by using an ICP dry recess etching process.  the threshold voltages of the devices showed +3% variation across three-inch wafers.  The extrinsic tranconductance and cutoff frequency of the PHEMT devices were 50 mS/mm and 82 GHz, respectively.  The minimum noise figure of the PHEMT devices was observed around 80% of the saturation drain current at 30 GHz and Vds=2V.  The devices exhibited and Fmin as low as 0.99 dB with an associated gain of 9.1 dB at 30 GHz.  We have successfully fabricated 0.1 W power amplifier operating at 25.4 GHz operational frequency using the processes described above.  We believe that the uniform device characteristics obtained across wafer are attributed to the gate recess etch process with the uniformity less than 3% achieved by using ICP technology.




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