Analysis of the Current Transport Characteristics (CTCs) in the Au/n-Si Schottky Diodes (SDs) with Al<sub>2</sub>O<sub>3</sub> Interfacial Layer over Wide Temperature Range
A. Büyükbaş-Uluşan, A. Tataroğlu, S. Altındal-Yerişkin
Abstract
Temperature dependent electrical-parameters and CTCs in Au/Al 2 O 3 /n-Si SDs have been analysed between 200 K and 400 K using current/voltage (IV) characteristics. While the value of quality/ideality factor (n) decreases, zero bias potential barrier height (BH, Φ B0 ) increases with increasing temperature. The value of Richardson constant (A * ) and activation energy (E a ) were also derived from the conventional Richardson plot (RP) as 0.567 eV and 7.34 × 10 −3 A.cm −2 K −2 , respectively. This low A * value shows that deviation from standard thermionic-emission (TE) model and to determine whether this situation may be described by Gaussian-distribution (GD) model or not, Φ Bo vs n and Φ Bo vs q/(2kT) curves were illustrated. The <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mover accent="true"> <mml:mi mathvariant="normal">Φ</mml:mi> <mml:mo>¯</mml:mo> </mml:mover> </mml:math> B value was found as 1.19 eV from the linear Φ B0 vs n plot for ideal case (n = 1). The mean-value of BH ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msub> <mml:mrow> <mml:mover accent="true"> <mml:mi mathvariant="normal">Φ</mml:mi> <mml:mo>¯</mml:mo> </mml:mover> </mml:mrow> <mml:mrow> <mml:mi mathvariant="normal">B</mml:mi> <mml:mn>0</mml:mn> </mml:mrow> </mml:msub> </mml:math> ) and standart deviation ( σ s ) values were found from the Φ Bo vs q/(2kT) curve as 1.130 eV and 0.127 V, respectively. By using value of σ s , RP was modified and then <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msub> <mml:mrow> <mml:mover accent="true"> <mml:mi mathvariant="normal">Φ</mml:mi> <mml:mo>¯</mml:mo> </mml:mover> </mml:mrow> <mml:mrow> <mml:mi mathvariant="normal">B</mml:mi> <mml:mn>0</mml:mn> </mml:mrow> </mml:msub> </mml:math> and A * values were found as 1.128 eV and 108.88 Acm −2 K −2 , respectively, and this value of A* very close to its theoretical value (=112 Acm −2 K −2 ). The surface state density (N ss ) were also obtained from the forward bias IV data for three-temperatures.