TY - JOUR
T1 - Improved free-standing GaN Schottky diode characteristics using chemical mechanical polishing
AU - Arjunan, Arul Chakkaravarthi
AU - Singh, Deepika
AU - Wang, H. T.
AU - Ren, F.
AU - Kumar, Purushottam
AU - Singh, R. K.
AU - Pearton, S. J.
PY - 2008/12/30
Y1 - 2008/12/30
N2 - Chemical mechanical polishing of free-standing GaN substrates is found to reduce the reverse leakage current of Ni/Au Schottky diodes fabricated on the Ga-face. The barrier height extracted from current-voltage measurements is found to increase from ∼0.4 eV on un-treated substrates to 0.75 eV on polished wafers, along with a reduction in diode ideality factor from 2 to 1.5. The electrical measurements are consistent with removal of a defective near-surface region that promotes generation-recombination current. More acidic polishing solutions were found to produce the best Schottky diode characteristics and there was an optimum loading force during CMP of the GaN surface.
AB - Chemical mechanical polishing of free-standing GaN substrates is found to reduce the reverse leakage current of Ni/Au Schottky diodes fabricated on the Ga-face. The barrier height extracted from current-voltage measurements is found to increase from ∼0.4 eV on un-treated substrates to 0.75 eV on polished wafers, along with a reduction in diode ideality factor from 2 to 1.5. The electrical measurements are consistent with removal of a defective near-surface region that promotes generation-recombination current. More acidic polishing solutions were found to produce the best Schottky diode characteristics and there was an optimum loading force during CMP of the GaN surface.
KW - Al O
KW - GaN
UR - http://www.scopus.com/inward/record.url?scp=56949087619&partnerID=8YFLogxK
U2 - 10.1016/j.apsusc.2008.08.096
DO - 10.1016/j.apsusc.2008.08.096
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AN - SCOPUS:56949087619
SN - 0169-4332
VL - 255
SP - 3085
EP - 3089
JO - Applied Surface Science
JF - Applied Surface Science
IS - 5 PART 2
ER -