TY  - JOUR
AU  - Mikulics, M.
AU  - Fox, A.
AU  - Marso, M.
AU  - Grützmacher, D.
AU  - Donoval, D.
AU  - Kordos, P.
TI  - Electrical and structural characterization of AlGaN/GaN field-effect transistors with recessed gate
JO  - Vacuum
VL  - 86
IS  - 6
SN  - 0042-207X
CY  - Amsterdam [u.a.]
PB  - Elsevier Science
M1  - PreJuSER-22690
SP  - 754 - 756
PY  - 2012
N1  - The work reported here was supported by the Slovak Scientific Grant Agency VEGA (Contract Nos. 1/0866/11 and 2/0098/09) and the Centre of Excellence CENAMOST (VVCE-0049-07).
AB  - Performance of AlGaN/GaN heterostructure field-effect transistors (HFETs) with recessed gate was investigated and compared with non-recessed counterparts. Optimal dry etch conditions by plasma assisted Ar sputtering were found for similar to 6 nm gate recess of a 20 nm thick AlGaN barrier layer. A decrease of the residual strain after the gate recessing (from -0.9 GPa to -0.68 GPa) was evaluated from the photoluminescence measurement. The saturation drain current at the gate voltage V-G = 1 V decreased from 1.05 A/mm to 0.85 A/mm after the recessing. The gate voltage for a maximal transconductance (240-250 mS/mm) has shifted from -3 V for non-recessed HFETs to -0.2 V for recessed counterparts. Similarly, the threshold voltage increased after the gate recessing. A decrease of the sheet charge density from 1 x 10(13) cm(-2) to 4 x 10(12) cm(-2) at V-G = 0 V has been evaluated from the capacitance measurements. The RF measurements yielded a slight increase of the cut-off frequencies after the gate recessing. All these indicate that the gate recessing is a useful tool to optimize the AlGaN/GaN HFET performance for high-frequency applications as well as for the preparation of normally-off devices. (C) 2011 Elsevier Ltd. All rights reserved.
KW  - J (WoSType)
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000301018400042
DO  - DOI:10.1016/j.vacuum.2011.07.016
UR  - https://juser.fz-juelich.de/record/22690
ER  -