Optimization of recessed ohmic contacts for AlGaN/AlN/GaN heterostructures using C(V) characterization of MSHM structures
Journal article, 2011

Recess etching is used to reduce the resistance of ohmic contacts to an AlGaN/AlN/GaN heterostructure. The minimization of the resistance relies on exact etching of the barrier. For this purpose C(V) measurements of the etched contacts, before annealing, are used to characterize the effect of the recess etch. Using the C(V) measurements a Cl2/Ar based ICP/RIE etch recipe with a stabilized etch rate of approximately 3 Å/s is developed. By utilizing the recess etch the contact resistivity is reduced from the non etched 0.9 Ω•mm to 0.3 Ω•mm when approximately 2 nm remains of the barriers, while maintaining a low sheet resistance. The C(V) measurements make it possible to monitor sheet carrier density vs. etch depth. Furthermore, the C(V) measurement gives large-area average values that is not easily obtained with AFM measurements.

AlGaN/GaN

recess etch

ohmic contact

heterostructure

Author

Martin Fagerlind

Chalmers, Microtechnology and Nanoscience (MC2), Microwave Electronics

Niklas Rorsman

Chalmers, Microtechnology and Nanoscience (MC2), Microwave Electronics

Physica Status Solidi (C) Current Topics in Solid State Physics

1862-6351 (ISSN) 1610-1642 (eISSN)

Vol. 8 7-8 2204-2206

Areas of Advance

Nanoscience and Nanotechnology (2010-2017)

Subject Categories

Electrical Engineering, Electronic Engineering, Information Engineering

Other Electrical Engineering, Electronic Engineering, Information Engineering

More information

Created

10/7/2017