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Determination of the mean and the homogeneous barrier height of Cu Schottky contacts on heteroepitaxial β‐Ga 2 O 3 thin films grown by pulsed laser deposition
Author(s) -
Splith Daniel,
Müller Stefan,
Schmidt Florian,
von Wenckstern Holger,
van Rensburg Johan Janse,
Meyer Walter E.,
Grundmann Marius
Publication year - 2014
Publication title -
physica status solidi (a)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.532
H-Index - 104
eISSN - 1862-6319
pISSN - 1862-6300
DOI - 10.1002/pssa.201330088
Subject(s) - thermionic emission , schottky barrier , materials science , schottky diode , schottky effect , homogeneous , deposition (geology) , pulsed laser deposition , band diagram , analytical chemistry (journal) , thin film , chemistry , optoelectronics , band gap , nanotechnology , diode , electron , physics , thermodynamics , paleontology , chromatography , quantum mechanics , sediment , biology
Abstract We have investigated the electrical properties of Cu Schottky contacts (SCs) on ( 2 ¯ 01 )‐oriented β‐Ga 2 O 3 thin films, which have been grown by pulsed laser deposition (PLD). The I – V characteristics of two different sample structures exhibit rectification ratios at ±2 V up to 7 orders of magnitude. The dominant current transport mechanism is thermionic emission. By fitting the I – V characteristics, we obtained the ideality factor n and the effective barrier heightΦ B effat temperatures between 50 and 320 K. Considering a Gaussian barrier height distribution, we determined a mean barrier height of 1.32 eV. The contacts are stable at high temperatures up to at least 550 K. At this temperature a homogeneous barrier height of 1.32 eV is found, consistent with the determined mean barrier height. The ideality factor for this temperature is 1.03 and barrier inhomogeneities do not influence current transport, making the contact close to ideal. Schematic band diagram of a Cu/β‐Ga 2 O 3 Schottky contact at a temperature of 550 K. The inset shows a photographic image of the sample.