Determination of the mean and the homogeneous barrier height of Cu Schottky contacts on heteroepitaxial β‐Ga2O3 thin films grown by pulsed laser deposition. Issue 1 (18th November 2013)

• Record Type: Journal Article
• Authors: Splith, Daniel; Müller, Stefan; Schmidt, Florian; von Wenckstern, Holger; van Rensburg, Johan Janse; Meyer, Walter E.; Grundmann, Marius
• Is Part Of: Physica status solidi. Volume 211:Issue 1(2014:Jan.)
• Page Start: 40
• Page End: 47
• Publication Date: 2013-11-18
• Subjects: Solid state physics -- Periodicals; Solids -- Industrial applications -- Periodicals; 530.41
• DOI: 10.1002/pssa.201330088
• Languages: English
• ISSNs: 1862-6300

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <sec id="pssa201330088-sec-0001" sec-type="section"> <p>We have investigated the electrical properties of Cu Schottky contacts (SCs) on (<alternatives><inline-graphic mimetype="image" xlink:href="ark:/27927/pgg40d209mt" xlink:type="simple" xmlns:xlink="http://www.w3.org/1999/xlink" /><mml:math altimg="urn:x-wiley:18626300:media:pssa201330088:pssa201330088-math-0001" display="inline" overflow="scroll" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mover accent="true"><mml:mn>2</mml:mn><mml:mo>¯</mml:mo></mml:mover><mml:mn>01</mml:mn></mml:mrow></mml:math></alternatives>)‐oriented β‐Ga<sub>2</sub>O<sub>3</sub> thin films, which have been grown by pulsed laser deposition (PLD). The <italic>I</italic>–<italic>V</italic> 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 <italic>I</italic>–<italic>V</italic> characteristics, we obtained the ideality factor <italic>n</italic> and the effective barrier height <alternatives><inline-graphic mimetype="image" xlink:href="ark:/27927/pgg40d209k8" xlink:type="simple" xmlns:xlink="http://www.w3.org/1999/xlink" /><mml:math altimg="urn:x-wiley:18626300:media:pssa201330088:pssa201330088-math-0002" display="inline" overflow="scroll" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msubsup><mml:mi>Φ</mml:mi><mml:mi mathvariant="normal">B</mml:mi><mml:mrow><mml:mtext>eff</mml:mtext></mml:mrow></mml:msubsup></mml:mrow></mml:math></alternatives> at 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. <inline-graphic xlink:href="ark:/27927/pgg40d201h1" content-type="pssa201330088-gra-0001" xlink:type="simple" xmlns:xlink="http://www.w3.org/1999/xlink" /></p> <p>Schematic band diagram of a Cu/β‐Ga<sub>2</sub>O<sub>3</sub> Schottky contact at a temperature of 550 K. The inset shows a photographic image of the sample.</p> </sec> </abstract>