Temperature dependent electrical characterisation of Pt/HfO2/n-GaN metal-insulator-semiconductor (MIS) Schottky diodes

Abstract

This paper reports an improvement in Pt/n-GaN metal-semiconductor (MS) Schottky diode characteristics by the introduction of a layer of HfO2 (5 nm) between the metal and semiconductor interface. The resulting Pt/HfO2/n-GaN metal-insulator-semiconductor (MIS) Schottky diode showed an increase in rectification ratio from 35.9 to 98.9(@ 2V), increase in barrier height (0.52 eV to 0.63eV) and a reduction in ideality factor (2.1 to 1.3) as compared to the MS Schottky. Epitaxial n-type GaN films of thickness 300nm were grown using plasma assisted molecular beam epitaxy (PAMBE). The crystalline and optical qualities of the films were confirmed using high resolution X-ray diffraction and photoluminescence measurements. Metal-semiconductor (Pt/n-GaN) and metal-insulator-semiconductor (Pt/HfO2/n-GaN) Schottky diodes were fabricated. To gain further understanding of the Pt/HfO2/GaN interface, I-V characterisation was carried out on the MIS Schottky diode over a temperature range of 150 K to 370 K. The barrier height was found to increase (0.3 eV to 0.79 eV) and the ideality factor decreased (3.6 to 1.2) with increase in temperature from 150 K to 370 K. This temperature dependence was attributed to the inhomogeneous nature of the contact and the explanation was validated by fitting the experimental data into a Gaussian distribution of barrier heights.

High Voltage Graphene Nanowall Trench MOS Barrier Schottky Diode Characterization for High Temperature Applications

“…From Figure 7c and Table 1, we can see that with higher temperature, ф B increases for both GNW and TiSi 2 TMBS diodes. This characteristic is also reported in several papers with different types of metal and semiconductor materials used in the experiments [32,35,[39][40][41][42][43]. The change in ф B value can be explained by Tung's model of barrier inhomogeneity [44].…”

Schottky Barrier Diode Characteristics of Graphene-GaN Heterojunction with Hexagonal Boron Nitride Interfacial Layer

“…The value of n deceases with increase in temperature, while ϕ B increases from 0.77 to 0.98 eV in the temperature range of 298–373 K, respectively. Higher barrier height was obtained for the graphene/n‐GaN SBD device with hBN interfacial layer . The high barrier height can be related to the inhibited static charge transfer process between graphene and n‐type GaN in presence of the h‐BN layer at the interface .…”

“…Figure c shows the variation of resistance in the bias voltage range of 0.8 to 2V with respect to temperature (298–373 K). The series resistance ( R S ) was also found to be strongly dependent on the applied bias and temperature, where the R S decreased with increase in temperature . The values of ideality factor ( n ) and barrier height (ϕ B ) were determined using the thermion equation (TE) from the J–V characteristics with change in temperature.…”

“…The conventional SBD device structure consists of a direct contact between the metal and semiconductor resulting in a metal‐semiconductor (MS) SBD . There are also many studies on the metal‐insulator‐semiconductor (MIS) based SBD in particular owing to the advantage in lowering the reverse saturation current . The GaN based MIS structure has been used for switching devices, where the presence of the insulating layer would provide lower leakage current and reducing power consumption .…”

Nanopaper‐Based Organic Inkjet‐Printed Diodes

“…To quantify the energy barrier, temperature dependent I – V measurements were performed between 243.15 and 343.15 K. Field‐assisted thermal emission of carriers over the energy barrier at a metal/insulator interface defines the Schottky conduction. The energy barrier height can be extracted by the slope of the conventional Richardson plot62 where I 0 is the reverse saturation current extrapolated from the straight‐line intercept of ln( I ) at V = 0.8 V. Figure S7 in the Supporting Information reports the characterization for the PT2 50 /UTDots structure. A barrier height of around 0.25 eV was extracted.…”