The determination of modified barrier heights in Ti/GaN nano-Schottky diodes at high temperature.
We have investigated the size-effect of the nano-Schottky diodes on the electrical transport properties and the temperature-dependent current transport mechanism in a metal-semiconductor nanowire junction (a Ti/GaN nano-Schottky diode) using current-voltage characterization in the range of 300-423 K. We found that the modified mean Schottky barrier height (SBH) was approximately 0.7 eV with a standard deviation of approximately 0.14 V using a Gaussian distribution model of the barrier heights. The slightly high value of the modified mean SBH (approximately 0.11 eV) compared to the results from the thin-film based Ti/GaN Schottky diodes could be due to an additional oxide layer at the interface between the Ti and GaN nanowires. Moreover, we found that the abnormal behavior of the barrier heights and the ideality factors in a Ti/GaN nano-Schottky diode at a temperature below 423 K could be explained by a combination of the enhancement of the tunneling current and a model with a Gaussian distribution of the barrier heights.
Lee
Seung-Yong
SY
Department of Semiconductor Science and Technology, SPRC, Chonbuk National University, Jeonju 561-756, Korea.
Kim
Tae-Hong
TH
Chol
Nam-Kyu
NK
Seong
Han-Kyu
HK
Choi
Heon-Jin
HJ
Ahn
Byung-Guk
BG
Lee
Sang-Kwon
SK