New approach for an accurate Schottky Barrier Height's extraction by I-V-T measurements

Abstract

This paper proposes a diagnostic tool dedicated to the analysis of the Schottky Barrier Height (SBH). The proposed method is mainly relevant for studying gate related failure mechanisms in electronic devices. In this case, the SBH of gallium nitride High Electron Mobility Transistors (HEMTs) is investigated in terms of mean SBH's value and dispersion. It is shown that according to given temperature and gate current ranges, linear relationships can be extracted between the mean SBH and the inhomogeneities that appear in forward-biased diode. These behaviors are able to highlight different kind of defects, revealing possible weaknesses of the devices.

Gate defects analysis in AlGaN/GaN devices by mean of accurate extraction of the Schottky Barrier Height, electrical modelling, T-CAD simulations and TEM imaging

“…From [5], the determination of the mean SBH and a related dispersion ( , ) is found not to be sufficient to get the Schottky Barrier Height determined accurately. By varying the IGS current range (considering a 2-decades window) or by changing the temperature, it is demonstrated that:…”

“…Since we are talking about diodes and non-destructive techniques, the most common approach consists in the analysis of the SBH. This part of the work is based on prior studies [4] [5], which present an accurate tool for extracting the SBH alone, through the quantification of the defects impact on the global SBH. The technique from [5] brings information about a mean SBH and its relative dispersion (inhomogeneity of the barrier, Fig.…”

“…Concerning the extraction's accuracy of the mean SBH associated to the method proposed in [5], it has been established that:…”

“…An original reinterpretation of the pairs ( , ) has been proposed in [5] by plotting versus for all the 'x' sliding windows of two decades of ∆IGS ( Fig. 6 a and b).…”

Non-destructive techniques for evaluating the reliability of high frequency active devices

“…The induced degradation during HTRB stress impacts the 1/f noise source (electron carrier fluctuation in the leakage conduction path), and thus the leakage current IG can be used as a dependable marker of reliability for device selection. A unified model has been developed to account for the gate Schottky barrier height inhomogeneity [28], for the thermal evolution of the IG-VGS plots and for the trap effects on the transient characteristics IGS(time) and IDS(time) [29]. In addition to these electrical and noise characterizations, TCAD models have been developed to successfully account for the physical origin of the evolutions on drain current and gate leakage current [30,31].…”