Compositionally graded channel HEMTs towards improved linearity for low-noise RF amplifiers
Paper i 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
Författare
A. Papamichail
Linköpings universitet
A. R. Persson
Linköpings universitet
Steffen Ricther
Lunds universitet
Linköpings universitet
Philipp Kuhne
Linköpings universitet
Per O.Å. Persson
Linköpings universitet
Mattias Thorsell
Chalmers, Mikroteknologi och nanovetenskap, Mikrovågselektronik
Saab
Hans Hjelmgren
Elektroteknik, datateknik, IT samt Industriell ekonomi
Niklas Rorsman
Chalmers, Mikroteknologi och nanovetenskap, Mikrovågselektronik
Vanya Darakchieva
Linköpings universitet
Lunds universitet
2022 Compound Semiconductor Week, CSW 2022
9781665453400 (ISBN)
2022 Compound Semiconductor Week, CSW 2022
Ann Arbor, USA,
Ann Arbor, USA,
Ämneskategorier
Annan fysik
Annan elektroteknik och elektronik
Den kondenserade materiens fysik
DOI
10.1109/CSW55288.2022.9930457