Influence of Spacer Thickness on the Noise Performance in InP HEMTs for Cryogenic LNAs
Journal article, 2022

InP high electron mobility transistors (InP HEMTs) with different spacer thickness 1 to 7 nm in the InAlAs-InGaAs heterostructure have been fabricated and characterized at 5 K with respect to electrical dc and rf properties. The InP HEMT noise performance was extracted from gain and noise measurements of a hybrid low-noise amplifier (LNA) at 5 K equipped with discrete transistors. When biased for optimal noise operation, the LNA using 5 nm spacer thickness InP HEMTs achieved the lowest average noise temperature of 1.4 K at 4-8 GHz. The InP HEMT channel noise was estimated from the drain noise temperature which confirmed the minimum in noise temperature for the 5 nm spacer thickness InP HEMT. It is suggested that the spacer thickness acts to control the degree of real-space transfer of electrons from the channel to the barrier responsible for the observed noise variation in the cryogenic InP HEMTs.

low-noise amplifier

spacer thickness





Junjie Li

Chalmers, Microtechnology and Nanoscience (MC2), Terahertz and Millimetre Wave Laboratory

Arsalan Pourkabirian

Low Noise Factory AB

Johan Bergsten

Low Noise Factory AB

Niklas Wadefalk

Low Noise Factory AB

Jan Grahn

Chalmers, Microtechnology and Nanoscience (MC2), Terahertz and Millimetre Wave Laboratory

IEEE Electron Device Letters

0741-3106 (ISSN) 15580563 (eISSN)

Vol. 43 7 1029-1032

Subject Categories

Other Chemical Engineering

Other Physics Topics

Signal Processing



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