Current transport mechanisms and trap state investigations in (Ni/Au)–AlN/GaN Schottky barrier diodes

Abstract

a b s t r a c tThe current transport mechanisms in (Ni/Au)-AlN/GaN Schottky barrier diodes (SBDs) were investigated by the use of current-voltage characteristics in the temperature range of 80-380 K. In order to determine the true current transport mechanisms for (Ni/Au)-AlN/GaN SBDs, by taking the J s(tunnel) , E 0 , and R s as adjustable fit parameters, the experimental J-V data were fitted to the analytical expressions given for the current transport mechanisms in a wide range of applied biases and at different temperatures. Fitting results show the weak temperature dependent behavior in the saturation current and the temperature independent behavior of the tunneling parameters in this temperature range. Therefore, it has been concluded that the mechanism of charge transport in (Ni/Au)-AlN/GaN SBDs, along the dislocations intersecting the space charge region, is performed by tunneling.In addition, in order to analyze the trapping effects in (Ni/Au)-AlN/GaN SBDs, the capacitance-voltage (C-V) and conductance-voltage (G/x-V) characteristics were measured in the frequency range 0.7-50 kHz. A detailed analysis of the frequency-dependent capacitance and conductance data was performed, assuming the models in which traps are located at the heterojunction interface. The density (D t ) and time constants (s t ) of the trap states have been determined as a function of energy separation from the conduction-band edge (E c À E t ) as D t ffi ð5-8Þ Â 10 12 eV À1 cm À2 and s t ffi ð43-102Þ ls, respectively.

Effect of AlN growth temperature on trap densities of in-situ metal-organic chemical vapor deposition grown AlN/AlGaN/GaN metal-insulator-semiconductor heterostructure field-effect transistors

“…On the other hand, τ T-AlGaN for MIS-diodes A and B were between (2 -6 μs) and (5 -8 μs) respectively. These τ T-AlN and τ T-AlGaN are consistent with the τ T ranges generally reported for AlN related traps, 21 and AlGaN related bulk traps. 3 The trap state energy level (E T ) is proportional to the τ T , and therefore it can be deduced using the expression,…”

Preparation and electrical characterization of Au/n-Si (1 1 0) structure with PVA–nickel acetate composite film interfacial layer

“…The slope of this plot also provides a second determination of R s , which can be used to check the consistency of this approach. 20 The values of R s and n of samples MS and MPS obtained from dV=d lnðIÞvs. I plots according to Equation ( 3) are given in Table 1.…”

“…In this case, while the donor type N SS is in effect near the conductance band, the acceptor type N SS is in effect near the valance band. 20 The electrical properties of the MPS diode under various illumination intensities Figure 6 shows the forward and reverse bias I-V characteristics at logarithmic scale of the Au/PVA(Nidoped)/n-Si MPS SD, measured in dark and at various illumination levels at room temperature. The forward current at high bias region increases with the increasing illumination intensity.…”

Determination of current transport and trap states density in AlInGaN/GaN heterostructures

“…The number of studies has been reported in the literature about the identification and elimination methods of the trap states in the GaN layer [21], AlGaN/GaN [11,12,16,17,19,20,23,24] AlInN/GaN [18,22], and AlN/GaN [25] heterostructures using frequency-voltage dependent capacitance and conductance measurement. Zhu et al [23] investigated the trap states in AlGaN/GaN Schottky-gate high-electron-mobility transistors (S-HEMTs) and Al 2 O 3 /AlGaN/GaN metal-oxide-semiconductor HEMTs (MOS-HEMTs).…”

“…Semra et al [25] reported a study on trap states in researching the gate-source contact on AlGaN/GaN HEMT by performing capacitance and conductance measurements at a temperature between 83 K and 370 K with the bias voltage maintained at 0 V. The interface trap state density and time constant were deduced using an analysis of the frequency dispersion in capacitance and conductance data. They established a traps state model with two levels of traps at the AlGaN/GaN interface and one level located in the barrier AlGaN surface with reported trap state values of 10 12 cm −2 eV −1 and a time constant varying between 1 μs and 3 ms.…”