scholarly journals Electrical Properties of Rapidly Annealed Ir and Ir/Au Schottky Contacts on n-Type InGaN

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
V. Rajagopal Reddy ◽  
B. Prasanna Lakshmi ◽  
R. Padma

The effect of annealing temperature on electrical characteristics of iridium (Ir) and iridium/gold (Ir/Au) Schottky contacts to n-type InGaN have been investigated by means of current-voltage (I-V) and capacitance-voltage (C-V) techniques. It is observed that the barrier height of Ir/n-InGaN and Au/Ir/n-InGaN Schottky diodes increases after annealing at 300∘C for 1 min in N2 ambient compared to the as-deposited. However, the barrier heights are found to be decreased somewhat after annealing at 500∘C for the both Ir and Ir/Au Schottky contacts. From the above observations, it is clear that the optimum annealing temperature for both Ir and Ir/Au Schottky contacts is 300∘C. Moreover, the barrier height (ϕb), ideality factor (n) and series resistance (RS) are determined using Cheung’s and Norde methods. Besides, the energy distribution of interface state densities are determined from the forward bias I-V characteristics by taking into account the bias dependence of the effective barrier height. Based on the above results, it is clear that both Ir and Ir/Au Schottky contacts exhibit a kind of thermal stability during annealing.

2014 ◽  
Vol 5 (3) ◽  
pp. 823-836 ◽  
Author(s):  
Bhaskar Reddy M

The influence of rapid thermal annealing on the electrical and structural properties of Au/Cr/n-InP Schottky diode havebeen investigated by the current-voltage (I-V), capacitance-voltage (C-V), auger electron spectroscopy (AES) and X-raydiffraction (XRD) measurements. The Schottky barrier height (SBH) and ideality factor (n) of the as-deposited Au/Cr/n-InPSchottky diode are 0.51 eV (I-V)/0.64 eV (C-V) and 1.81, respectively. When the contact is annealed at 200 oC in N2atmosphere for 1min, a maximum SBH (0.71 eV (I-V)/0.81 eV (C-V)) and low ideality factor (1.15) are achieved for theAu/Cr/n-InP Schottky diode. However, after annealing at 300 oC, the SBH slightly decreases to 0.58 eV (I-V)/0.69 eV (CV),and ideality factor increases to 1.45, respectively. The SBHs obtained from the Norde and Cheung’s methods areclosely matched with those obtained from the I-V method. Results show that the optimum annealing temperature for theAu/Cr/n-InP Schottky diode is 200 °C. Further, the discrepancy between SBHs calculated from I-V and C-V methods isalso discussed. Moreover, the energy distribution of interface state density is estimated from forward bias I-Vcharacteristics at different annealing temperatures. AES and XRD studies reveal that the formation of indium (In) phasesat Au/Cr and InP interface may be the cause for the increase in SBH after annealing at 200 oC. The AFM results show thatthe overall surface morphology of Au/Cr Schottky contacts is considerably smooth at elevated tempratures.


1992 ◽  
Vol 260 ◽  
Author(s):  
T. S. Huang ◽  
J. G. Peng ◽  
C. C. Lin

ABSTRACTThe interfacial stability, surface morphology and electrical characteristics of MoAlx contacts to n-GaAs have been investigated by using x-ray diffraction, scanning electron microscopy, sheet resistance and current-voltage measurements. The compositions of rf-cosputtered MoAlx films were x = 0.35, 2.7, and 7.0, respectively. The contacts were annealed by rapid thermal processing in the temperature range 500–1000 °C for 20 s. The interfaces of MoAl0.35/GaAs and MoAl2,7/GaAs were stable up to 900 °C, while the interfaces of MoAl7.0/GaAs were less stable and reactions occurred above 800 °C. The variations of sheet resistances and the barrier heights of the Schottky diodes as a function of annealing temperatures can be well correlated to the interfacial stability. The MoAl2.7/n-GaAs diodes exhibited the best stability and were characterized by the highest barrier height (0.98 V) and nearly unit ideality factor (1.11) after annealing at 900 °C. For all thermally stable MoAlx/n-GaAs Schottky diodes, the barrier heights increased with annealing temperature.


2021 ◽  
Vol 13 (7) ◽  
pp. 1318-1323
Author(s):  
Myeong-Cheol Shin ◽  
Dong-Hyeon Kim ◽  
Seong-Woo Jung ◽  
Michael A. Schweitz ◽  
Sang-Mo Koo

ABSTRACTThis study report on the formation of AlN/SiC heterostructure Schottky diodes for use of temperature sensing applications enhance the sensitivity. We analyzed the sensitivity of the AlN/SiC Schottky diode sensor depending on the annealing temperature. AlN/4H-SiC Schottky diodes were fabricated by depositing aluminum nitride (AlN) thin film on 4H/SiC by radio frequency sputtering. The forward bias electrical characteristics were determined under DC bias (in the voltage range of 0–1.5 V). The ideality factor, barrier height, and sensitivity were derived through current–voltage–temperature (I–V–T) measurements in the temperature range of 300–500 K. The sensitivity of the AlN/4H-SiC Schottky barrier diode ranged from 2.5–5.0 mV/K.


2014 ◽  
Vol 778-780 ◽  
pp. 710-713 ◽  
Author(s):  
Hamid Amini Moghadam ◽  
Sima Dimitrijev ◽  
Ji Sheng Han

This paper presents a physical model based on interface traps to explain both the larger barrier heights of practical Schottky diodes in comparison to the theoretically expected values and the appearance of a knee in the log I–V characteristics. According to this model, acceptor-type interface traps near the valance band increase the Schottky barrier height, which shifts the log I–V characteristic to higher forward-bias voltages. In addition to the acceptor traps, donor-type interface traps can appear near the conduction band, and when they do, they cause the knee in the log I–V characteristics as their energy level falls below the Fermi level and the charge associated with these traps changes from positive to neutral.


2018 ◽  
Vol 25 (04) ◽  
pp. 1850082 ◽  
Author(s):  
NEZIR YILDIRIM ◽  
ABDULMECIT TURUT ◽  
HULYA DOGAN

The Schottky barrier type Ni/[Formula: see text]-GaAs contacts fabricated by us were thermally annealed at 600[Formula: see text]C and 700[Formula: see text]C for 1[Formula: see text]min. The apparent barrier height [Formula: see text] and ideality factor of the diodes were calculated from the forward bias current–voltage characteristic in 60–320[Formula: see text]K range. The [Formula: see text] values for the nonannealed and 600[Formula: see text]C and 700[Formula: see text]C annealed diodes were obtained as 0.80, 0.81 and 0.67[Formula: see text]eV at 300[Formula: see text]K, respectively. Thus, it has been concluded that the reduced barrier due to the thermal annealing at 700[Formula: see text]C promises some device applications. The current preferentially flows through the lowest barrier height (BH) with the temperature due to the BH inhomogeneities. Therefore, it was seen that the [Formula: see text] versus [Formula: see text] plots for the nonannealed and annealed diodes showed the linear behavior according to Gaussian distributions.


1996 ◽  
Vol 449 ◽  
Author(s):  
Michèle T. Hirsch ◽  
Kristin J. Duxstad ◽  
E. E. Haller

ABSTRACTWe report the effect of mild annealing on Ti Schottky diodes on n-type GaN. The Ti films were deposited by electron beam evaporation on n-type GaN grown by metal organic vapor deposition. We determine the effective barrier height Ф60 by current-voltage measurements as a function of temperature. The as-deposited Ti contacts show rectifying behavior with low barrier heights Ф60 ≤ 200meV. At annealing temperatures as low as 60°C we observe an increase of the barrier height to values of 250meV. After annealing at 230°C and above a stable barrier height of 450meV is measured. The increase in barrier height is not due to any macroscopic interfacial reaction. The origin of the observed changes are discussed in terms of the Schottky-Mott model and possible microscopic interfacial reactions.


Author(s):  
R. Padma ◽  
V. Rajagopal Reddy

The electrical properties of the Ir/Ru Schottky contacts on n-InGaN have been investigated by current-voltage (I-V), capacitance-voltage (C-V), capacitance-frequency (C-f) and conductance-frequency (G-f) measurements. The obtained mean barrier height and ideality factor from I-V are 0.61 eV and 1.89. The built-in potential, doping concentration and barrier height values are also estimated from the C-V measurements and the corresponding values are 0.62 V, 1.20x1017 cm-3 and 0.79 eV, respectively. The interface state density (NSS) obtained from forward bias I-V characteristics by considering the series resistance (RS) values are lower without considering the series resistance (RS). Furthermore, the interface state density (NSS) and relaxation time (tau) are also calculated from the experimental C-f and G-f measurements. The NSS values obtained from the I-V characteristics are almost three orders higher than the NSS values obtained from the C-f and G-f measurements. The experimental results depict that NSS and tau are decreased with bias voltage. The frequency dependence of the series resistance (RS) is attributed to the particular distribution density of interface states. DOI: 10.21883/FTP.2017.12.45189.8340


1998 ◽  
Vol 512 ◽  
Author(s):  
H. S. Venugopalan ◽  
S. E. Mohney

ABSTRACTThe barrier heights of Ni/Ga/Ni and Re Schottky contacts to n-GaN were investigated by current-voltage (I-V) and capacitance-voltage (C-V) measurements. The elemental Ni contacts were also investigated for comparison. The Ni/Ga/Ni and Re diodes were stable on short term annealing up to 700 °C. It was also shown that the Ni/Ga/Ni (84 at% Ni, 16 at% Ga) diodes were more stable than Ni diodes. This work provides the first demonstration of Schottky diodes to n-GaN that are stable upon annealing at 700 °C.


2018 ◽  
Vol 25 (01) ◽  
pp. 1850043
Author(s):  
A. KORKUT

It is well known that the semiconductor surface is easily oxidized by air-media in time. This work studieds the characterization of Schottky diodes and changes in depletion capacitance, which is caused by air exposure of a group of Cu/n-Si/Al Schottky diodes. First, data for current-voltage and capacitance-voltage were a Ren, and then ideality factor, barrier height, built-in potential ([Formula: see text], donor concentration and Fermi level, interfacial oxide thickness, interface state density were calculated. It is seen that depletion capacitance was calculate; whereafter built-in potential played an important role in Schottky diodes characteristic. Built-in potential directly affects the characteristic of Schottky diodes and a turning point occurs. In case of forward and reverse bias, depletion capacitance versus voltage graphics are matched, but in an opposite direction. In case of forward bias, differential depletion capacitance begins from minus values, it is raised to first [Formula: see text], then reduced to second [Formula: see text] under the minus condition. And it sharply gones up to positive apex, then sharply falls down to near zero, but it takes positive values depending on DC voltage. In case of reverse bias, differential depletion capacitance takes to small positive values. In other respects, we see that depletion characteristics change considerably under DC voltage.


2019 ◽  
Vol 963 ◽  
pp. 506-510
Author(s):  
Michael Schneider ◽  
Laura Stöber ◽  
Jens P. Konrath ◽  
Florian Patocka ◽  
Ulrich Schmid

In this paper, the impact of substrate preconditioning by ion bombardment in-situ in a conventional sputter equipment on n-doped 4H-silicon carbide (SiC) Schottky diodes with molybdenum nitride metallization is studied. By variation of the plasma power during argon ion bombardment, the effective barrier height is adjustable in the range from 0.66 to 0.96 eV, as deduced by current / voltage measurements over a wide temperature range. Therefore, this approach offers a straightforward method to tailor the Schottky barrier height over a significant range by introducing an insitu substrate pretreatment step available in most sputter equipment.


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