Influence of $$\hbox {Si}_{3}\hbox {N}_{4}$$ Si 3 N 4 layer on the electrical properties of Au/n-4H SiC diodes

Abstract

In this study, the effect of Si 3 N 4 insulator layer on the electrical characteristics of Au/n-4H SiC diode was investigated. The current-voltage (I −V), capacitance-voltage (C−V) and conductance-voltage (G/w−V) measurements were carried out at room temperature condition. Under thermionic emission model, electrical parameters as zero-bias barrier height (Bo), ideality factor (n), interface states (D it), and series (R s) and shunt (R sh) resistances were estimated from forward bias I −V analyses. The values of n and Bo were about 1.305 and 0.796 eV for metal-semiconductor (MS) rectifying diode, and 3.142 and 0.713 eV for metal-insulator-semiconductor (MIS) diode with the insertion of Si 3 N 4 layer, respectively. Since the values of n were greater than the unity, the fabricated diodes showed non-ideal I −V behaviour. The energy distribution profile of D it of the diodes was calculated by taking into account of the bias dependence of the effective barrier height (e) and R s. The obtained D it values with R s are almost one order of magnitude lower than those without R s for two diodes. According to Cheung's model, R s were calculated and these values were found in increasing behaviour with the contribution of Si 3 N 4 insulator layer. In addition, the J R −V plot behaviours with linear dependence between ln(J R) vs. V 0.5 indicated that the dominant conduction mechanism in the reverse bias region was Schottky effect for both MS and MIS diodes. In the room temperature C−V measurements, different from the results of MIS diode, the values of C for MS diode was observed in decreasing behaviour from ideality with crossing the certain forward bias voltage point (∼2.5 V). The decrease in the negative capacitance corresponds to the increase of G/w.

Characteristics of 21H-SiC Thin Film-Based Schottky Barrier Diodes Using TiN Contacts

“…19 It is also observed that the presence of an intermediate layer (Si 3 N 4 ) between metal and SiC leads to the formation of an MIS structure, resulting in a decrease in barrier height and ideality factor. 20 The results on 6H, 4H, 3C SiC-based SBDs reveal that variation of Schottky parameters with temperature can be correlated with the presence of inhomogeneity at the metal/SiC interface, variation in local interfacial structure, and roughness at an atomic level in the metal/semiconductor interface. 7,21,22 A recent study by Zeghdar et al reported spatial inhomogeneity in the diode and temperature dependence of Schottky barrier height and ideality factor of a Mo/4H-SiC interface assuming a Gaussian distribution of the barrier height.…”

Effect of atomic-layer-deposited HfO2 thin-film interfacial layer on the electrical properties of Au/Ti/n-GaAs Schottky diode

“…As an initial step to determine basic electrical properties from I-V plots for a diode with and without interfacial layer (MIS diode), thermionic emission (TE) equation was used. For this type of diodes, it can be expressed as [13,28,34,79]…”

“…That is why the researchers started working on different interface layers to reduce leakage current of MIS diodes [33][34][35]. Due to the high leakage current problem of SiO2 layer, highdielectric materials have been a point of interest in Schottky-type and MIS diodes.…”

“…Active dangling bonds at Si semiconductor surface had still problems on passivation processes [32,34]. Therefore, new materials alternative to SiO2 and different deposition methods have been also point of interest.…”

“…MS and MIS diodes are crucial to indicate the electrical properties in wide range frequency and temperature to detail the interface homogeneity and nature transport mechanism [32][33][34]. The basic electrical properties of these diodes are extracted according to thermionic emission (TE) theory.…”