Compositionally graded channel HEMTs towards improved linearity for low-noise RF amplifiers
Paper in proceeding, 2022
Although AlGaN/GaN HEMTs with high power and current gain have been demonstrated in RF device applications, at high signal operation they show an inherent non-linear behavior which leads to gain compression and signal distortion. Polarization-doped AlGaN/GaN HEMTs, with a compositionally graded channel enables a linear response improvement through formation of a 3-D electron gas. In this work, we develop the growth process for graded channel HEMTs in a hot-wall MOCVD reactor. Control of the grading profile is established through growth parameter tuning. Afterwards, analysis by EDS allows for precise determination of Al composition across the channel. Conventional and graded channel HEMT structures were fabricated and characterized. Furthermore, the sheet resistance, carrier density and mobility in HEMT structures with different grading profiles are compared and discussed. The conventional (non-graded) structure revealed the highest electron mobility of ~2350 cm2/V.s, which is among the highest values reported.
polarization doping
RF devices
graded channel HEMTs
Author
A. Papamichail
Linköping University
A. R. Persson
Linköping University
Steffen Ricther
Lund University
Linköping University
Philipp Kuhne
Linköping University
Per O.Å. Persson
Linköping University
Mattias Thorsell
Chalmers, Microtechnology and Nanoscience (MC2), Microwave Electronics
Saab
Hans Hjelmgren
Electric, Computer, IT and Industrial Engineering
Niklas Rorsman
Chalmers, Microtechnology and Nanoscience (MC2), Microwave Electronics
Vanya Darakchieva
Linköping University
Lund University
2022 Compound Semiconductor Week, CSW 2022
9781665453400 (ISBN)
2022 Compound Semiconductor Week, CSW 2022
Ann Arbor, USA,
Ann Arbor, USA,
Subject Categories
Other Physics Topics
Other Electrical Engineering, Electronic Engineering, Information Engineering
Condensed Matter Physics
DOI
10.1109/CSW55288.2022.9930457