Effect of Doping on the Interface States in Au Schottky Contact to p-In0.21Ga0.79As Grown on GaAs by Metal Organic Vapour Phase Epitaxy

1993 ◽  
Vol 318 ◽  
Author(s):  
A. Singh ◽  
P. Cova ◽  
R. A. MASUT
Keyword(s):  
Doping Concentration ◽  
Schottky Diodes ◽  
Forward Bias ◽  
Schottky Contact ◽  
Frequency Dispersion ◽  
Vapour Phase ◽  
Interface State ◽  
Interface States ◽  
Vapour Phase Epitaxy ◽  
Order Of Magnitude

ABSTRACTEpitaxial p-In0.21Gao0.79As/Au Schottky barrier type diodes were fabricated by evaporation of Au on chemically etched surfaces of In0.21Ga0.79As:Zn layers grown on highly doped GaAs substrate by MOVPE. 1 MHz capacitance-voltage (C-V) and Capacitance-frequency (C-f) measurements were performed in the frequency range 1 KHz-1 MHz at room temperature in Au Schottky diodes made on four epitaxial In0.2 Ga0.79As:Zn samples with doping concentrations between 6×1014cm−3 and 4×1017 cm−3. Under forward bias, a large frequency dispersion in the junction capacitance was observed which was attributed to the interface states in thermal equilibrium with the semiconductor. The interface states capacitance extracted from the C-f data was analyzed in terms of Lehovec's theoretical model of interface state continuum with single time constant, and the characteristic parameters of the interface states (energy density (Nss), relaxation time (τ) and hole capture cross-section (σh)) were determined. In the samples with doping concentration in the range 1.5×1017-4.3×1017 cm−3, Nss was about an order of magnitude higher than in the sample having a doping concentration of 5.8×1014 cm−3. Over the interface states energy range 0.40-0.65 eV, Nss decreased exponentially with energy in the highly doped samples and σh increased with energy in all the samples.

Improvement of the Refractory Metal/n-GaAs Interface by Low Temperature Anneal

1996 ◽  
Vol 448 ◽  
Author(s):  
A. Singh ◽  
L. Velásquez
Keyword(s):  
Ideality Factor ◽  
Forward Bias ◽  
Rf Sputtering ◽  
Frequency Dispersion ◽  
Interface States ◽  
Frequency Variation ◽  
Saturation Current ◽  
Zero Bias ◽  
Heat Treated ◽  
Schottky Junctions

AbstractThe W/n-GaAs Schottky junctions A and B of area 1.75×l0-2 cm2 were fabricated by deposition of W on the chemically etched polished surfaces of n-GaAs samples by rf sputtering using a rf powers of 300 Watt for 30 min. The W contact B was subjected to a 90 min. thermal anneal at 390 °C. The room temperature I-V and C-V/f (with 200 Hz < f < 1 MHz) measurements were carried out for both the as-deposited and thermally annealed W/n-GaAs Schottky junctions A and B, respectively. From the direct I-V data, the values of 1.09 and 8.1×10-8 A for the ideality factor (n) and the reverse saturation current (Io), respectively, were estimated for the diode B, compared to the values of n=1.70 and Io=6.3×10-6 A for the diode A. The observed frequency dispersion in the zero bias capacitance in the diode B was attributed to fast interface states with a time constant, τ2=6 μs and density, Nss2=5.8×1010 eV-1cm-2, whereas, both the slow interface states (with τ1=4 ms and density, Nss1=7.8×1012 eV-1cm-2) and fast states (with τ2=1 μs and density Nss2=8.6×1010 eV-1cm-2) were responsible for the observed frequency variation of the zero bias capacitance in the diode A. For the forward bias values in the range 20-100 mV, the frequency dispersion in the measured capacitance suggested the presence of both the fast and slow interface states (with time constants differing by three orders of magnitude) in the as-deposited and the heat treated W/n-GaAs interfaces. Thermal anneal at 390 °C for 90 min. lowered the density of states at the W/n-GaAs interface by two orders of magnitude and resulted in the formation of a high quality rectifying W contact to n-GaAs with a rectification ratio of 1.4×104, a low Io and an ideality factor close to unity.

Electrical Properties of Au/Bi4-xLaxTi3O12 Thin Film/Si Structures and Reduction of Interface States

2005 ◽  
Vol 902 ◽  
Author(s):  
Atsushi Kohno ◽  
Hiroyuki Tomari
Keyword(s):  
Interfacial Layer ◽  
Sol Gel ◽  
Frequency Dispersion ◽  
Interface State ◽  
Interface States ◽  
State Density ◽  
Flat Band ◽  
Silicon Substrates ◽  
Ft Ir ◽  
The Ideal

AbstractSub-100nm-Thick Polycrystalline Bi4-xLaxTi3O12 (BLT) thin films have been formed on silicon substrates by sol-gel and spin-coating techniques. The analysis of X-ray reflectivity for the BLT/Si structure showed that the BLT film density was slightly lower than the ideal value and the interfacial layer was formed. By Fourier transform infrared spectroscopy (FT-IR) it is confirmed that the formation of the interfacial layer was due to oxidation of Si. Clockwise hysteresis was observed in capacitance-voltage (C-V) characteristics for Au/BLT/p-Si structures at a frequency range between 1 MHz – 1 kHz. The frequency dispersion of the C-V curve was caused by a large amount of interface states at BLT/Si interface. As the film was crystallized at 550°C for 2 h the maximum interface state density was ∼3.4×1011 cm-2ev-1 at 1 kHz. Also, the negative gate-voltage shift of the C-V curve from the ideal curve and the gate-bias dependence of the flat-band voltage were observed, resulting in the presence of undesirable positive charges in the film and the electron injection to the traps near the BLT/Si interface. By post-annealing of the device at 400 °C in oxygen atmosphere the interface states (fast sates) were successfully reduced to a third of the initial value and also the positive charges were significantly diminished.

Current Induced Degradation of a-Si:H Pin and Schottky Switches

1992 ◽  
Vol 258 ◽  
Author(s):  
K.J.B.M. Nieuwesteeg ◽  
J. Boogaard ◽  
G. Oversluizen
Keyword(s):  
Reverse Bias ◽  
Schottky Diodes ◽  
Forward Bias ◽  
Schottky Contact ◽  
Reverse Current ◽  
Bias Current ◽  
Hole Injection ◽  
Carrier Injection ◽  
Degradation Behaviour ◽  
Current Stress

ABSTRACTForward-bias current stress experiments were performed on α-Si:H p-i-n and Schottky switches at several temperatures and at current densities up to 6 A/cm2. In Schottky diodes, current stressing results in a lowering of the forward-bias SCLC current together with an increase of its thermal activation energy. The reverse current is unaffected. The rate of degradation of the forward current increases with increasing temperature. From a comparison of the degradation behaviour of Schottky's with different barrier height we find that the rate of degradation is correlated to the minority-carrier injection ratio of the Schottky contact. The effects are interpreted as being due to metastable state creation in the bulk α-Si:H. The rectifying properties of the metal-to-semiconductor contact are relatively stable to current stress.The forward-bias I-V curves of p-i-n diodes degrade much faster than those of the Schottky switches. At the same time, the reverse-bias current increases due to the stress. The lower stability to current-stress of p-i-n diodes is ascribed to the much higher hole injection in the mesa. After a short time, the reverse-bias current becomes dominated by e-h generation from the created deep states in the i-layer and then gives a direct indication of its time dependence.

Electrical Characteristics of Pt Schottky Contact to Semipolar (11-22) n-GaN Depending on Si Doping Concentration

2013 ◽  
Vol 404 ◽  
pp. 146-151
Author(s):  
Sung Min Jung ◽  
Kyoung Kook Kim ◽  
Sung Nam Lee ◽  
Hyun Soo Kim
Keyword(s):  
Carrier Transport ◽  
Doping Concentration ◽  
Schottky Diodes ◽  
Schottky Contact ◽  
Surface States ◽  
Incident Beam ◽  
Electrical Characteristics ◽  
X Ray ◽  
Si Doping ◽  
Thermionic Field Emission

Electrical characteristics of Pt Schottky contact formed on semipolar (11-22) n-type GaN planes with different Si doping concentration were investigated. Large Si doping to semipolar (11-22) n-GaN led to improved electrical and structural properties, e.g., the Hall mobility (μ) was increased by 35 % and the full width at half maximum (FWHM) of X-ray rocking curves with X-ray incident beam direction of [-1-12 was decreased by 34 %. Thermionic field emission (TFE) theory applied to the forward current-voltage (I-V) curves of fabricated Pt Schottky diodes yielded the Schottky barrier height (ΦB) of 1.64 and 1.84 eV, the tunneling parameter (E00) of 44 and 65 meV, and the ideality factor (n) of 1.83 and 2.57 for the lowly doped and highly doped samples, respectively, indicating that the Si doping affected the carrier transport properties substantially associated with the change of surface states density.

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
Keyword(s):  
Barrier Height ◽  
Annealing Temperature ◽  
Schottky Diodes ◽  
Forward Bias ◽  
Interface State ◽  
Schottky Contacts ◽  
Barrier Heights ◽  
Current Voltage ◽  
State Densities ◽  
Optimum Annealing Temperature

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.

Effect of RF Power on the Characteristic Parameters of W/n-GaAs Schottky Contacts Fabricated by RF Sputtering

1995 ◽  
Vol 378 ◽  
Author(s):  
A. Singh ◽  
G. Aroca ◽  
L. Velásquez
Keyword(s):  
Surface Defects ◽  
Defect Density ◽  
Forward Bias ◽  
Schottky Contact ◽  
Rf Sputtering ◽  
Low Frequency ◽  
Schottky Contacts ◽  
Rf Power ◽  
Order Of Magnitude ◽  
Density Surface

AbstractW/n-GaAs/In Schottky contacts of area 1.75 mm2 were fabricated by deposition of W on (100) n-GaAs by rf Sputtering using rf power values in the range 200–400 Watt. The I-V and high frequency C-V measurements at 300 K, in the 200 Watt W/n-GaAs Schottky contact indicated that W formed a good rectifying contact to n-GaAs, with a rectification ratio (r) of 270, ideality factor (n) of 1.39, reverse saturation current (Io) of 1.2×10−6 A and the C-V barrier height (φbo) of 1.6 V. However, n and Io increased, whereas r and φbo decreased for the W/n-GaAs Schottky contacts prepared using higher rf power. For the 300 Watt W/n-GaAs contact, the values of 70, 1.70, 6.3}10−6 A, and 1.2V for r, n, Io and φbo, respectively, were estimated. The low frequency forward bias capacitance (or surface defect density) was an order of magnitude higher in the 300 Watt contact than in the 200 Watt contact. This fact suggested that the degradation in the quality of W/n-GaAs Schottky contacts fabricated by using high rf power was caused by high density surface defects created during sputter deposition of W on n-GaAs.

Influence of the Oxidation Temperature and Atmosphere on the Reliability of Thick Gate Oxides on the 4H-SiC C(000-1) Face

2008 ◽  
Vol 600-603 ◽  
pp. 597-602 ◽  
Author(s):  
Michael Grieb ◽  
Dethard Peters ◽  
Anton J. Bauer ◽  
Peter Friedrichs ◽  
Heiner Ryssel
Keyword(s):  
Interface State ◽  
Interface States ◽  
Oxide Semiconductor ◽  
Constant Current ◽  
Flat Band ◽  
Flat Band Voltage ◽  
Gate Oxides ◽  
Order Of Magnitude ◽  
State Densities ◽  
Density Of Interface States

The reliability of thermal oxides grown on n-type 4H-SiC C(000-1) face wafer has been investigated. In order to examine the influence of different oxidation atmospheres and temperatures on the reliability, metal-oxide-semiconductor capacitors were manufactured and the different oxides were characterized by C-V measurements and constant-current-stress. The N2O-oxides show the smallest flat band voltage shift compared to the ideal C-V curve and so the lowest number of effective oxide charges. They reveal also the lowest density of interface states in comparison to the other oxides grown on the C(000-1) face, but it is still higher than the best oxides on the Si(000-1) face. Higher oxidation temperatures result in smaller flat band voltage shifts and lower interface state densities. Time to breakdown measurements show that the charge-to-breakdown value of 63% cumulative failure for the N2O-oxide on the C(000-1) face is more than one order of magnitude higher than the highest values measured on the Si(000-1) face. Therefore it can be concluded that a smaller density of interface states results in a higher reliability of the oxide.

4H-SiC Trench Schottky Diodes for Next Generation Products

2013 ◽  
Vol 740-742 ◽  
pp. 781-784 ◽  
Author(s):  
Qing Chun Jon Zhang ◽  
Jennifer Duc ◽  
Van Mieczkowski ◽  
Brett Hull ◽  
Scott Allen ◽  
...  
Keyword(s):  
Leakage Current ◽  
Doping Concentration ◽  
Schottky Diodes ◽  
Size Reduction ◽  
High Current ◽  
Next Generation ◽  
Electrical Field ◽  
Reverse Leakage Current ◽  
Chip Size ◽  
Order Of Magnitude

A novel trench JBS structure has been developed to reduce the electrical field at the Schottky interface. Compared to the conventional planar JBS structure, the new design has reduced the reverse leakage current by 1 order of magnitude at rated voltage. The much reduced field at the Schottky interface allows an increase in the drift doping concentration, which enables a significant chip size reduction on next generation SiC Schottky diodes. This progress makes it possible to fabricate high current rating (>50 A) SiC diodes for module applications.

On electrical and interfacial properties of iron and platinum Schottky barrier diodes on (111) n-type Si0.65Ge0.35

2018 ◽  
Vol 32 (09) ◽  
pp. 1850097 ◽  
Author(s):  
D. Hamri ◽  
A. Teffahi ◽  
A. Djeghlouf ◽  
D. Chalabi ◽  
A. Saidane
Keyword(s):  
Schottky Barrier ◽  
Low Voltage ◽  
Series Resistance ◽  
Schottky Diodes ◽  
Forward Bias ◽  
Reverse Current ◽  
Interface States ◽  
Schottky Barrier Diodes ◽  
Shunt Resistance ◽  
Voltage Frequency

Current–voltage (I–V), capacitance–voltage–frequency (C–V–f) and conductance–voltage–frequency (G/[Formula: see text]–V–f) characteristics of Molecular Beam Epitaxy (MBE)-deposited Fe/n-Si[Formula: see text]Ge[Formula: see text] (FM1) and Pt/[Formula: see text]-Si[Formula: see text]Ge[Formula: see text](PM2) (111) orientated Schottky barrier diodes (SBDs) have been investigated at room-temperature. Barrier height ([Formula: see text]), ideality factor (n) and series resistance (R[Formula: see text]) were extracted. Dominant current conduction mechanisms were determined. They revealed that Poole–Frenkel-type conduction mechanism dominated reverse current. Differences in shunt resistance confirmed the difference found in leakage current. Under forward bias, quasi-ohmic conduction is found at low voltage regions and space charge-limited conduction (SCLC) at higher voltage regions for both SBDs. Density of interface states (N[Formula: see text]) indicated a difference in interface reactivity. Distribution profiles of series resistance (R[Formula: see text]) with bias gives a peak in depletion region at low-frequencies that disappears with increasing frequencies. These results show that interface states density and series resistance of Schottky diodes are important parameters that strongly influence electrical properties of FM1 and PM2 structures.

scholarly journals Silicon carbide schottky diodes forward and reverse current properties upon fast electron radiation

2019 ◽  
Vol 8 (2) ◽  
pp. 428-437
Author(s):  
M. Azim Khairi ◽  
Rosminazuin Ab. Rahim ◽  
Norazlina Saidin ◽  
Yusof Abdullah ◽  
Nurul Fadzlin Hasbullah
Keyword(s):  
Silicon Carbide ◽  
Electron Irradiation ◽  
Ideality Factor ◽  
Reverse Bias ◽  
Series Resistance ◽  
Schottky Diodes ◽  
Forward Bias ◽  
Bias Current ◽  
Saturation Current ◽  
Order Of Magnitude

This paper investigates on the reaction of 10 and 15MGy, 3MeV electron irradiation upon off-the-shelves (commercial) Silicon Carbide Schottky diodes from Infineon Technologies (model: IDH08SG60C) and STMicroelectronics (model: STPSC806). Such irradiation reduces the forward-bias current. The reduction is mainly due to the significant increase of the series resistance (i.e. Infineon: 1.45Ω at before irradiation → 121×103 Ω at 15MGy); STMicroelectronics: 1.44Ω at before irradiation → 2.1×109 Ω at 15MGy). This increase in series resistance gives 4.6 and 8.2 orders of magnitude reduction for the forward-bias current density of Infineon and STMicroelectronics respectively. It is also observed that the ideality factor and the saturation current of the diodes increases with increasing dose (i.e. ideality factor- Infineon: 1.01 at before irradiation → 1.05 at 15MGy; STMicroelectronics: 1.02 at before irradiation → 1.3 at 15MGy | saturation current- Infineon: 1.6×10-17A at before irradiation → 2.5×10-17A at 15MGy; STMicroelectronics: 2.4×10-15A at before irradiation → 8×10-15A at 15MGy). Reverse-bias leakage current density in model by Infineon increases by one order of magnitude after 15MGy irradiation, however, in model by STMicroelectronics decreases by one order of magnitude. Overall, for these particular samples studied, Infineon devices have shown to be better in quality and more radiation resistance toward electron irradiation in forward-bias operation while STMicroelectronics exhibit better characteristics in reverse-bias operation.

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