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1.
《Materials Science in Semiconductor Processing》2012,15(5):480-485
In order to evaluate current conduction mechanism in the Au/n-GaAs Schottky barrier diode (SBD) some electrical parameters such as the zero-bias barrier height (BH) Φbo(I–V) and ideality factor (n) were obtained from the forward bias current–voltage (I–V) characteristics in wide temperature range of 80–320 K by steps of 10 K. By using the thermionic emission (TE) theory, the Φbo(I–V) and n were found to depend strongly on temperature, and the n decreases with increasing temperature while the Φbo(I–V) increases. The values of Φbo and n ranged from 0.600 eV and 1.51(80 K) to 0.816 eV and 1.087 (320 K), respectively. Such behavior of Φbo and n is attributed to Schottky barrier inhomogeneities by assuming a Gaussian distribution (GD) of BHs at Au/n-GaAs interface. In the calculations, the electrical parameters of the experimental forward bias I–V characteristics of the Au/n-GaAs SBD with the homogeneity in the 80–320 K range have been explained by means of the TE, considering GD of BH with linear bias dependence. 相似文献
2.
Polycrystalline thin films of ternary ZnIn2Se4 compound with p-type conductivity were deposited on a pre-deposited aluminium (Al) film by a flash evaporation technique. A Schottky diode comprising of Al/p-ZnIn2Se4 structure was fabricated and characterized in the temperature range 303–323 K in dark condition. The Schottky diode was subjected to current (I)-voltage (V) and capacitance (C)-voltage (V) characterization. The Al/p-ZnIn2Se4 Schottky diode showed behaviour typical of a p-n junction diode. The devices showed very good diode behaviour with the rectification ratio of about 105 at 1.0 V in dark. The Schottky diode ideality factor, barrier height, carrier concentration, etc. were derived from I-V and C-V measurements. At lower applied voltages (V≤0.5 V), the electrical conduction was found to take place by thermionic emission (TE) whereas at higher voltages (V>0.5 V), a space charge limited conduction mechanism (SCLC) was observed. An energy band diagram was constructed for fabricated Al/p-ZnIn2Se4 Schottky diode. 相似文献
3.
The electrical analysis of Ni/n-GaP structure has been investigated by means of current–voltage (I–V), capacitance–voltage (C–V) and capacitance–frequency (C–f) measurements in the temperature range of 120–320 K in dark conditions. The forward bias I–V characteristics have been analyzed on the basis of standard thermionic emission (TE) theory and the characteristic parameters of the Schottky contacts (SCs) such as Schottky barrier height (SBH), ideality factor (n) and series resistance (Rs) have been determined from the I–V measurements. The experimental values of SBH and n for the device ranged from 1.01 eV and 1.27 (at 320 K) to 0.38 eV and 5.93 (at 120 K) for Ni/n-GaP diode, respectively. The interface states in the semiconductor bandgap and their relaxation time have been determined from the C–f characteristics. The interface state density Nss has ranged from 2.08 × 1015 (eV?1 m?2) at 120 K to 2.7 × 1015 (eV?1 m?2) at 320 K. Css has increased with increasing temperature. The relaxation time has ranged from 4.7 × 10?7 s at 120 K to 5.15 × 10?7 s at 320 K. 相似文献
4.
《Materials Science in Semiconductor Processing》2009,12(6):224-232
In this study, we have examined Au/TiO2/n-Si Schottky barrier diodes (SBDs), in order to interpret in detail the experimental observed non-ideal current–voltage–temperature (I–V–T) characteristics. I–V characteristics were measured in the wide temperature range of 80–400 K. TiO2 was deposited on n-Si substrate by reactive magnetron sputtering. The zero-bias barrier height (ϕB0) and ideality factor (n) show strong temperature dependence. While n decreases, ϕB0 increases with increasing temperature. Experimental results show that the current across the SBDs may be greatly influenced by the existence of Schottky barrier height (SBH) inhomogeneity. These temperature behaviors have been explained on the basis of the thermionic emission (TE) theory with Gaussian distribution (GD) of the barrier heights (BHs) due to BH inhomogeneities at metal–semiconductor (M/S) interface. From this assumptions, obtaining Richardson constant value of the A* 121.01 A/cm2 K2 is perfect agreement with the theoretical value of 120 A/cm2 K2 for n-type Si. Hence, behaviors of the forward-bias I–V characteristics of the Au/TiO2/n-Si (SBDs) can be successfully explained on the basis of a TE mechanism with a double Gaussian distribution of the BHs. 相似文献
5.
This work describes a comparison of current density–voltage (J–V) and capacitance–voltage (C–V) properties measured as a function of temperature; deep trap properties are measured by deep level transient spectroscopy (DLTS) of Schottky diodes fabricated on n-type gallium nitride (GaN grown by metal organic vapor phase epitaxy (MOVPE). Unexpected behavior in the standard Richardson plot was observed in the temperature range 165–480 K, reflecting a range of Schottky barrier heights and a variation of ideality factor. This was explained by applying a Gaussian spatial distribution of barrier heights across the Schottky diode. C–V measurements were carried out in the temperature range 165–480 K to compare the temperature dependence of the barrier height with those obtained by the Gaussian distribution method. DLTS and high-resolution Laplace DLTS (LDLTS) show a majority carrier peak centered at 450 K. 相似文献
6.
The electrical characteristics of Al/strained Si-on-insulator (sSOI) Schottky diode have been investigated using current–voltage (I–V) and capacitance–voltage (C–V) measurements in the wide temperature range of 200–400 K in steps of 25 K. It was found that the barrier height (0.57–0.80 eV) calculated from the I–V characteristics increased and the ideality factor (1.97–1.28) decreased with increasing temperature. The barrier heights determined from the C–V measurements were higher than those extracted from the I–V measurements, associated with the formation of an inhomogeneous Schottky barrier at the interface. The series resistance estimated from the forward I–V characteristics using Cheung and Norde methods decreased with increasing temperature, implying its strong temperature dependence. The observed variation in barrier height and ideality factor could be attributed to the inhomogeneities in Schottky barrier, explained by assuming Gaussian distribution of barrier heights. The temperature-dependent I–V characteristics showed a double Gaussian distribution with mean barrier heights of 0.83 and 1.19 eV and standard deviations of 0.10 and 0.16 eV at 200–275 and 300–400 K, respectively. From the modified Richardson plot, the modified Richardson constant were calculated to be 21.8 and 29.4 A cm−2 K−2 at 200–275 and 300–400 K, respectively, which were comparable to the theoretical value for p-type sSOI (31.6 A cm−2 K−2). 相似文献
7.
The Pt nano-film Schottky diodes on Ge substrate have been fabricated to investigate the effect of annealing temperature on the characteristics of the device. The germanide phase between Pt nano-films and Ge substrate changed and generated interface layer PtGe at 573 K and 673 K, Pt2Ge3 at 773 K. The current–voltage(I - V) characteristics of Pt/n-Ge Schottky diodes were measured in the temperature range of 183–303 K. Evaluation of the I - V data has revealed an increase of zero-bias barrier height ΦB0 but the decrease of ideality factor n with the increase in temperature. Such behaviors have been successfully modeled on the basis of the thermionic emission mechanism by assuming the presence of Gaussian distributions. The variation of electronic transport properties of these Schottky diodes has been inferred to be attributed to combined effects of interfacial reaction and phase transformation during the annealing process. Therefore, the control of Schottky barrier height at metal/Ge interface is important to realize high performance Ge-based CMOS devices. 相似文献
8.
《Materials Science in Semiconductor Processing》2012,15(5):531-535
In this study, the main electrical parameters of Au/TiO2(rutile)/n-Si Schottky barrier diodes (SBDs) were analyzed by using current–voltage–temperature (I–V–T) characteristics in the temperature range 200–380 K. Titanium dioxide (TiO2) thin film was deposited on a polycrystalline n-type Silicon (Si) substrate using the DC magnetron sputtering system at 200 °C. In order to improve the crystal quality deposited film was annealed at 900 °C in air atmosphere for phase transition from amorphous to rutile phase. The barrier height (Φb) and ideality factor (n) were calculated from I–V characteristics. An increase in the value of Φb and a decrease in n with increasing temperature were observed. The values of Φb and n for Au/TiO2(rutile)/n-Si SBDs ranged from 0.57 eV and 3.50 (at 200 K) to 0.82 eV and 1.90 (at 380 K), respectively. In addition, series resistance (Rs) and Φb values of MIS SBDs were determined by using Cheung's and Norde's functions. Cheung's plots are obtained from the donward concave curvature region in the forward bias semi-logarithmic I–V curves originated from series resistance. Norde's function is easily used to obtain series resistance as a function of temperature due to current counduction mechanism which is dominated by thermionic emission (TE). The obtained results have been compared with each other and experimental results show that Rs values exhibit an unusual behavior that it increases with increasing temperature. 相似文献
9.
《Materials Science in Semiconductor Processing》2009,12(6):243-247
Experimental results of the fabricated Schottky barrier diode on a GaSe:Gd substrate are presented. The electrical analysis of Au–Sb/p-GaSe:Gd structure has been investigated by means of current–voltage (I–V) and capacitance–voltage (C–V) measurements at 296 K temperature. The diode ideality factor and the barrier height have been obtained to be 1.07 and 0.85 eV, respectively, by applying a thermionic emission theory. At high currents in the forward direction, the series resistance effect has been observed. The series resistance has been determined from I–V measurements using Cheung's method. 相似文献
10.
The dielectric properties of Ni/n-GaP Schottky diode were investigated in the temperature range 140–300 K by capacitance–voltage (C–V) and conductance–voltage (G/ω–V) measurements. The effect of temperature on series resistance (Rs) and interface state density (Nss) were investigated. The dependency of dielectric constant (ε′), dielectric loss (ε′′), loss tangent (tan δ), ac conductivity (σac), real (M′) and imaginary (M′′) parts of the electric modulus over temperature were evaluated and analyzed at 1 MHz frequency. The temperature dependent characteristics of ε′ and ε′′ reveal the contribution of various polarization effects, which increases with temperature. The Arrhenius plot of σac shows two activation energies revealing the presence of two distinct trap states in the chosen temperature range. Moreover, the capacitance–frequency (C–f) measurement over 1 kHz to 1 MHz was carried out to study the effect of localized interface states. 相似文献
11.
All RF sputtering-deposited Pt/SiO2/n-type indium gallium nitride (n-InGaN) metal–oxide–semiconductor (MOS) diodes were investigated before and after annealing at 400 °C. By scanning electron microscopy (SEM), the thickness of Pt, SiO2, n-InGaN layer was measured to be ~250, 70, and 800 nm, respectively. AFM results also show that the grains become a little bigger after annealing, the surface topography of the as-deposited film was smoother with the rms roughness of 1.67 nm and had the slight increase of 1.92 nm for annealed sample. Electrical properties of MOS diodes have been determined by using the current–voltage (I–V) and capacitance–voltage (C–V) measurements. The results showed that Schottky barrier height (SBH) increased slightly to 0.69 eV (I–V) and 0.82 eV (C–V) after annealing at 400 °C for 15 min in N2 ambient, compared to that of 0.67 eV (I–V) and 0.79 eV (C–V) for the as-deposited sample. There was the considerable improvement in the leakage current, dropped from 6.5×10−7 A for the as-deposited to 1.4×10−7 A for the 400 °C-annealed one. The annealed MOS Schottky diode had shown the higher SBH, lower leakage current, smaller ideality factor (n), and denser microstructure. In addition to the SBH, n, and series resistance (Rs) determined by Cheungs׳ and Norde methods, other parameters for MOS diodes tested at room temperature were also calculated by C–V measurement. 相似文献
12.
The electrical characteristics of Pd Schottky contacts on ZnO films have been investigated by current-voltage (I–V) and capacitance–voltage (C–V) measurements at different temperatures. ZnO films of two thicknesses (400 nm and 1000 nm) were grown by DC-magnetron sputtering on n-Si substrates. The basic structural, optical and electrical properties of these films are also reported. We compared the two Schottky diodes by means of characteristic parameters, such as rectification ratio, ideality factor (η), barrier height (Φb) and series resistance and obtained better results for the 1000 nm-ZnO Schottky diodes. We also discussed the dependence of I‐V characteristics on temperature and the two distinct linear regions observed at low temperatures are attributed to the existence of two different inhomogeneous barrier heights. From I–V plots in a log-log scale we found that the dominant current-transport mechanism at large forward bias is space-charge limited current (SCLC) controlled by the presence of traps within the ZnO bandgap. The existence of such traps (deep states or interface states) is demonstrated by frequency-dependent capacitance and deep-level transient spectroscopy (DLTS) measurements. 相似文献
13.
Bipolar switching phenomenon is found for Au/n-type CuAlOx/heavily doped p-type Si devices at temperatures above 220 K. For high or low resistive states (HRS or LRS), the electrical resistance is decreased with increasing temperature, indicating a semiconducting behavior. Carrier transport at LRS or HRS is dominated by hopping conduction. It is reasonable to conclude that the transition from HRS to LRS due to the migration of oxygen vacancies (VO) is associated with electron hopping mediated through the VO trap sites. The disappearance of the resistive switching behavior below 220 K is attributed to the immobile VO traps. The deep understanding of conduction mechanism could help to control the device performance. 相似文献
14.
《Organic Electronics》2014,15(9):2141-2147
This paper reports on the detail analysis of the DC electrical and photoelectrical properties of the high-efficient (η = 8.01% under standard 100 mW/cm2 AM1.5 illumination) small molecule bulk heterojunction (SM BHJ) solar cells p-DTS(FBTTh2)2/PC70BM. In this SM BHJ solar cell, the dark diode current is determined by the multistep tunnel-recombination via interface states at low forward bias (V < 0.65 V) and the interface state assisted thermionic emission at high forward bias (V > 0.65 V). The effect of illumination on the diode current was also quantitatively investigated. It was observed a reduced Shockley–Read–Hall recombination via interface states at large forward bias (from the maximum power point to the open-circuit conditions). The expression of the load I–V characteristic of the illuminated high-efficient SM BHJ solar cells was derived in the presence of the light dependent series and shunt resistance. 相似文献
15.
Thin film of lead dioxide, α-PbO2, has been grown by thermal evaporation technique on the single crystal of p-Si substrate and heterojunction photodiode, Au/α-PbO2/p-Si/Al, was fabricated. The current-voltage characteristics of the diode have been studied in the temperature ranged from 303 to 373 K and the voltage applied during measurements varied from −1 to 1.5 V. It was found from the (I-V) characteristics of the diode that the conduction mechanisms in the forward bias direction are controlled by the thermionic emission at bias potential ≤0.7 V followed by single trap space charge limited current (SCLC) conduction in the voltage range >0.7 V. The capacitance-voltage characteristics of the device were studied at room temperature in dark condition and it has been shown that the diode is abrupt junction. The carrier concentration on both sides of the depletion layer has been determined. Energy band diagram for α-PbO2/p-Si device was constructed. The device under illumination with light of intensity 20 W/m2 gives acceptable values of photoresponse parameters such as photosensitivity and photoconductivity. The presented photodiode parameters exhibit the typical photosensor applications with reproducibility phenomenon. 相似文献
16.
A Mo/n-type 6H-SiC/Ni Schottky barrier diode (SBD) was fabricated by sputtering Mo metal on n-type 6H-SiC semiconductor. Before the formation of Mo/n-type 6H-SiC SBD, an ohmic contact was formed by thermal evaporation of Ni on n-type 6H-SiC and annealing at 950 °C for 10 min. It was seen that the structure had excellent rectification. The electrical parameters were extracted using its current–voltage (I–V) and capacitance–voltage (C–V) measurements carried out at room temperature. Very high (1.10 eV) barrier height and 1.635 ideality factor values were reported for Mo/n-type 6H-SiC using ln I–V plot. The barrier height and series resistance values of the diode were also calculated as 1.413 eV and 69 Ω from Norde׳s functions, respectively. Furthermore, 1.938 eV barrier height value of Mo/n-type 6H-SiC SBD calculated from C–V measurements was larger than the one obtained from I–V data. 相似文献
17.
An Au/n–InP/In diode has been fabricated in the laboratory conditions and the current–voltage (I–V) and capacitance–voltage (C–V) characteristics of the diode have been measured in room temperature. In order to observe the effect of the thermal annealing, this diode has been annealed at temperatures 100 and 200 °C for 3 min in N2 atmosphere. The characteristic parameters such as leakage current, barrier height and ideality factor of this diode have been calculated from the forward bias I–V and reverse bias C–V characteristics as a function of annealing temperature. Also the rectifying ratio of the diode is evaluated for as-deposited and annealed diode. 相似文献
18.
M. Ben Karoui R. Gharbi N. Alzaied M. Fathallah E. Tresso L. Scaltrito S. Ferrero 《Solid-state electronics》2008,52(8):1232-1236
Schottky diodes realized on 4H–SiC n-type wafers with an epitaxial layer and a metal-oxide overlap for electric field termination were studied. The oxide was grown by plasma enhanced chemical vapor deposition (PECVD) and the Schottky barriers were formed by thermal evaporation of titanium or nickel. Diodes, with voltage breakdown as high as 700 V and ideality factor as low as 1.05, were obtained and characterized after packaging in standard commercial package (TO220).The electrical properties such as ideality factor, hight barrier, the series resistance Rs were deduced by current/voltage (I–V) analysis using the least mean square (LMS) method. The temperature effect on break voltage, Rs and saturation current was studied. A model based on two parallel Schottky diodes with two barrier heights is presented for some devices having an inhomogeneous contact. It is shown that the excess current at low voltage can be explained by a lowering of the Schottky barrier in localized regions. We use the two series RC components electrical model in order to study the dynamic behaviour of the Schottky diode in low frequency and to improve the effect of barrier inhomogeneities in electrical properties. 相似文献
19.
《Materials Science in Semiconductor Processing》2012,15(5):549-554
In this article, thermoelectric (TE) materials based on p-type Sb2Te3 samples and dispersed with x amounts of Bi (x=0.0, 0.2, 0.4, 0.6, 0.8, and 1.0) in the form Bi2xSb2(1−x)Te3 were synthesized via a standard solid-state microwave route. The microstructure of the ingots was characterized by field emission scanning electron microscopy. As-synthesized ingots were formed by the assembly of micro-sheet grains. The phase composition of the powders was characterized by X-ray diffraction, revealing a rhombohedral structure. The influence of variations in Bi content (x) on the TE properties of the resulting alloy was studied in the temperature range of 303 K to 523 K. Increases in x caused a decrease in hole concentration and electrical conductivity and an increase in Seebeck coefficient. A maximum power factor of 4.96 mW/mK2 was obtained at about 373 K for a Bi2xSb2(1−x)Te3 sample with x=0.2. 相似文献
20.
Phosphorus doped amorphous/nanocrystalline silicon (a-Si:H/nc-Si:H) thin films have been deposited by a filtered cathodic vacuum arc (FCVA) technique in the presence of hydrogen gas at different substrate temperatures (Ts) ranging from room temperature (RT) to 350 °C. The films have been characterized by using X-ray diffraction (XRD), Raman spectroscopy, Fourier transform infrared (FTIR) spectroscopy, dark conductivity (σD), activation energy (ΔE), optical band gap (Eg) and secondary ion mass spectroscopy. The XRD patterns show that RT grown film is amorphous in nature but high temperature (225 and 350 °C) deposited films exhibit nanocrystalline structure with (111) and (220) crystal orientations. The crystallite size of higher temperature grown silicon film evaluated was between 13 and 25 nm. Raman spectra reveal the amorphous nature of the film deposited at RT, whereas higher temperature deposited films show crystalline nature. The crystalline volume fraction of the silicon film deposited at higher temperatures (225 and 350 °C) was estimated to be 58 and 72%. With the increase of Ts, the bonding configuration changes from mono-hydride to di-hydride as revealed by the FTIR spectra. The values of σD, ΔE and Eg of silicon films deposited at different Ts were found to be in the range of 5.37×10−4–1.04 Ω−1 cm−1, 0.05–0.45 eV and 1.42–1.83 eV, respectively. Photoconduction of 3.5% has also been observed in n-type nc-Si:H films with the response and recovery times of 9 and 12 s, respectively. A n-type nc-Si:H/p-type c-Si heterojunction diode was fabricated which showed the diode quality factor between 1.6 and 1.8. 相似文献