Electron Trapping in Extended Defects in Microwave AlGaN/GaN HEMTs with Carbon-Doped Buffers
Artikel i vetenskaplig tidskrift, 2018

This paper investigates AlGaN/GaN high-electron mobility transistors (HEMTs) fabricated on epistructures with carbon (C)-doped buffers. Metalorganic chemical vapor deposition is used to grow two C-doped structures with different doping profiles, using growth parameters to change the C incorporation. The C concentration is low enough to result in n-type GaN. Reference devices are also fabricated on a structure using iron (Fe) as dopant, to exclude any process related variations and provide a relevant benchmark. All devices exhibit similar dc performance. However, pulsed I - V$ measurements show extensive dispersion in the C-doped devices, with values of dynamic R-mathrm-scriptscriptstyle ON 3 -4 times larger than in the dc case. Due to the extensive trapping, the devices with C-doped buffers can only supply about half the output power of the Fe-doped sample, 2.5 W/mm compared to 4.8 W/mm at 10 GHz. In drain current transient measurements, the trap filling time is varied, finding large prevalence of trapping at dislocations for the C-doped samples. Clusters of C around the dislocations are suggested to be the main cause for the increased dispersion.

dislocations

iron

GaN high-electron mobility transistor (HEMT)

Buffer doping

dispersion

carbon

Författare

Johan Bergsten

Chalmers, Mikroteknologi och nanovetenskap (MC2), Mikrovågselektronik

Mattias Thorsell

Mikrovågselektronik

David Adolph

Mikrovågselektronik

J. T. Chen

SweGaN AB

O. Kordina

SweGaN AB

E. O. Sveinbjornsson

Linköpings universitet

Háskóli Íslands

Niklas Rorsman

Mikrovågselektronik

IEEE Transactions on Electron Devices

0018-9383 (ISSN)

Vol. 65 6 2446-2453

Ämneskategorier

Oorganisk kemi

Materialkemi

Den kondenserade materiens fysik

DOI

10.1109/TED.2018.2828410

Mer information

Senast uppdaterat

2018-05-31