Analysis of leakage current mechanisms in Pt/Au Schottky contact on Ga-polarity GaN by Frenkel-Poole emission and deep level studies

Abstract

We report the Frenkel-Poole emission in Pt/Au Schottky contact on Ga-polarity GaN grown by molecular beam epitaxy using current-voltage-temperature (I-V-T) characteristics in the temperature ranging from 200 K to 375 K. Using thermionic emission model, the estimated Schottky barrier height is 0.49 eV at 200 K and 0.83 eV at 375 K, respectively, and it is observed that the barrier height increases with increase in temperature. The extracted emission barrier height (ϕt) for Ga-polarity GaN Schottky diode by Frenkel-Poole theory is about 0.15 eV. Deep level transient spectroscopy study shows a deep level with activation energy of 0.44 eV, having capture cross-section 6.09 × 10−14 cm2, which is located between the metal and semiconductor interface, and trap nature is most probably associated with dislocations in Ga-polarity GaN. The analysis of I-V-T characteristics represents that the leakage current is due to effects of electrical field and temperature on the emission of electron from a trap state near the metal-semiconductor interface into continuum states associated with conductive dislocations in Ga-polarity GaN Schottky diode.

The Variation of Schottky Barrier Height Induced by the Phase Separation of InAlAs Layers on InP HEMT Devices

“…In addition, the ideality factor n values for the LT-InAlAs were 13.1 at 77 K and 3.35 at 300 K We estimated SBH at 77 K and 300 K using thermionic emission theory from the J-V curve of an InAlAs Schottky diode. The thermionic current density-voltage relationship of a Schottky diode, neglecting series and shunt resistance [22,23], is given by:…”

Ultralow reverse leakage current in AlGaN/GaN lateral Schottky barrier diodes grown on bulk GaN substrate

“…The effective barrier height (ϕ b ) and ideality factor (n) of the L-SBDs can be extracted from the forward bias characteristics using the standard thermionic emission mechanisms. 11,12) In this study, the experimental values of ϕ b =n for the L-SBDs grown on the bulk GaN and sapphire substrates are 1.25 eV=1.60 and 0.96 eV=1.92, respectively. Furthermore, a much higher turn on voltage was observed for the L-SBD grown on the bulk GaN substrate when compared with that on the sapphire substrate, as shown by the linear plot of the forward currents in the inset of Fig.…”

“…The emission of electrons via a trap state into a continuum of states associated with the presence of conductive dislocations was the dominant leakage mechanism in an AlGaN= GaN L-SBD, 11,12) which could be successfully explained by the Frenkel-Poole emission model. The current density associated with Frenkel-Poole emission is given by…”

Modification of Schottky Barrier Properties of Ti/p-type InP Schottky Diode by Polyaniline (PANI) Organic Interlayer

“…Thus the barrier height obtained from the I-V method is significantly lower than the weighted arithmetic average of Schottky barrier heights obtained from the C-V method [36]. The downward concave curvature of the forward bias I-V characteristics at sufficiently large voltages has been attributed to the presence of the interface states (N ss ) which are in equilibrium with the semiconductor, apart from the effect of R s [18]. In this region, the ideality factor n is rather controlled by the interface states and the series resistance.…”

“…All evaporation processes were carried out under a vacuum pressure of 7 ´10 -7 torr. In the present work, we fabricated the metal contacts using metal shadow masks very carefully in order to minimize the physical and chemical damages of PANI occurring during standard photolithography process and is feasible for the investigation of forward and reverse I-V characteristics [17,18]. For comparison purposes, the conventional Ti/p-type InP Schottky diodes were fabricated under similar process conditions.…”