A Study of Inhomogeneous Schottky Diodes on n-Type 4H-SiC

2006 ◽  
Vol 527-529 ◽  
pp. 911-914 ◽  
Author(s):  
D.J. Ewing ◽  
Qamar-ul Wahab ◽  
Sergey P. Tumakha ◽  
Leonard J. Brillson ◽  
X.Y. Ma ◽  
...  
Keyword(s):  
Low Voltage ◽  
Deep Level ◽  
Schottky Diodes ◽  
Forward Bias ◽  
Polarized Light ◽  
Thermionic Emission ◽  
Chemical Vapor ◽  
Double Barrier ◽  
X Ray ◽  
Sic Wafer

In this study, we performed a statistical analysis of 500 Ni Schottky diodes distributed across a 2-inch, n-type 4H-SiC wafer with an epilayer grown by chemical vapor deposition. A majority of the diodes displayed ideal thermionic emission when under forward bias, whereas some diodes showed ‘double-barrier’ characteristics with a ‘knee’ in the low-voltage log I vs. V plot. X-ray topography (XRT) and polarized light microscopy (PLM) revealed no correlations between screw dislocations and micropipes and the presence of double-barrier diodes. Depth resolved cathodoluminescence (DRCLS) indicated that certain deep-level states are associated with the observed electrical variations.

Nanoscale Deep Level Defect Correlation with Schottky Barriers in 4H-SiC/Metal Diodes

2006 ◽  
Vol 527-529 ◽  
pp. 907-910
Author(s):  
Sergey P. Tumakha ◽  
L.M. Porter ◽  
D.J. Ewing ◽  
Qamar-ul Wahab ◽  
X.Y. Ma ◽  
...  
Keyword(s):  
Surface Defect ◽  
Deep Level ◽  
Polarized Light ◽  
Schottky Barriers ◽  
Double Barrier ◽  
Barrier Heights ◽  
Current Voltage ◽  
Cathodoluminescence Spectroscopy ◽  
Morphological Defects ◽  
Additional Defect

We have used depth-resolved cathodoluminescence spectroscopy (DRCLS) to correlate subsurface deep level emissions and double barrier current-voltage (I-V) characteristics across an array of Ni/4H-SiC diodes on the same epitaxial wafer. These results demonstrate not only a correspondence between these optical features and measured barrier heights, but they also suggest that such states may limit the range of SB heights in general. DRCLS of near-ideal diodes show a broad 2.45 eV emission at common to all diode areas and associated with either impurities or inclusions. Strongly non-ideal diodes exhibit additional defect emissions at 2.2 and 2.65 eV. On the other hand, there is no correlation between the appearance of morphological defects observed by polarized light microscopy or X-ray topography and the presence of double barrier characteristics. The DRCLS observations of defect level transitions that correlate with non-ideal Schottky barriers suggest that these sub-surface defect features can be used to predict Schottky barrier behavior.

Compositional Modulation and its Optoelectric Properties of Zn(S,Se,Te) Crystals Grown by Hydrogen Radical-Enhanced CVD

1995 ◽  
Vol 417 ◽  
Author(s):  
Hiroyuki Fujiwara ◽  
Toshihiro Ii ◽  
Isamu Shimizu
Keyword(s):  
Deep Level ◽  
Chemical Vapor ◽  
X Ray Diffraction ◽  
Small Shift ◽  
X Ray ◽  
Compositional Modulation ◽  
Peak Energy ◽  
Large Lattice ◽  
The Difference ◽  
Hydrogen Radical

AbstractHigh-quality (ZnS)n(ZnSe)12n and (ZnSe)n(ZnTe)11n (n=1∼4) crystals were grown at a low temperature of 200°C by hydrogen radical-enhanced chemical vapor deposition. From satellite peaks in x-ray diffraction spectra, these periodic structure crystals were confirmed to be grown coherently on substrates, in spite of large lattice mismatches between the grown layers and the substrates (͛=4∼7%). In photoluminescence (PL) spectra of these films, strong band-edge emissions were predominantly observed, resulting from a suppression of deep-level emissions. We found that the PL peak energy of (ZnSe)n(ZnTe)11n shifts systematically to lower energy by 200 meV with changes in the number of ZnSe layers (n), while relatively small shift of 13 meV was observed in (ZnS)n(ZnSe)12n. These discrepancy can be attributed to the difference of band-lineups or chemical natures of constituent atoms in these crystals.

Evaluation of On-State Resistance and Boron-Related Levels in n-Type 4H-SiC

2005 ◽  
Vol 483-485 ◽  
pp. 425-428 ◽  
Author(s):  
R.R Ciechonski ◽  
Samuele Porro ◽  
Mikael Syväjärvi ◽  
Rositza Yakimova
Keyword(s):  
Minority Carrier ◽  
Deep Level ◽  
Schottky Diodes ◽  
Depth Profiling ◽  
Thermionic Emission ◽  
Barrier Heights ◽  
Transient Spectroscopy ◽  
State Resistance ◽  
Thick Layers

Specific on-resistance Ron estimated from current density-voltage characteristics of Schottky diodes on thick layers exhibits variations from tens of mW.cm2 to tens of W.cm2 for different doping levels. In order to understand the occurrence of high on-state resistance, Schottky barrier heights were first estimated for both forward and reverse bias with the application of thermionic emission theory and were in agreement with a literature reported values. Decrease in mobility with the temperature was observed and its dependencies of T–1.3 and T–2.0 for moderately doped and low doped samples respectively were estimated. From deep level measurements by Minority Carrier Transient Spectroscopy, an influence of shallow boron related levels and D-center on dependence of on-state resistance was observed, being more pronounced in low doped samples. Similar tendency was observed in depth profiling of Ron. This suggests a major role of boron in a compensation mechanism thus resulting in high Ron.

Barrier Height Control and X-Ray Diffraction Study of Metal on Si1−Gex/Si Grown by Very Low Pressure CVD

1995 ◽  
Vol 402 ◽  
Author(s):  
Z. Q. Shiâ ◽  
L. He ◽  
Y. Zheng
Keyword(s):  
Schottky Barrier ◽  
Barrier Height ◽  
Schottky Diodes ◽  
Chemical Vapor ◽  
Low Pressure ◽  
Control Technique ◽  
X Ray Diffraction ◽  
X Ray ◽  
Height Control ◽  
Barrier Formation

AbstractThe potential application of epitaxial Si1−xGex, on Si in electronic and optoelectronic devices has led to an increased study of metal - Si1−xGex interaction and barrier height control technique. In this paper, we report the epitaxial growth of Si1−xGex on Si and the Schottky barrier formation processing. The Si1−xGex (x=0.17 and 0.20) layers were grown by rapid radiant heating, very low pressure chemical vapor deposition (VLPCVD). The crystal structure and epitaxial nature of the Si1−xGex, layers were studied by X-Ray diffraction. The value of full width at half maximum (FWHM) was found to be 0.34° for the as grown Si1−xGex (400) peak. The metal-Si1−xGex/Si Schottky diodes were formed by depositing Pd on Si1−xGex/Si at room temperature (RT=300K) and low temperature (LT=77K). The Schottky barrier heights and current transport mechanisms were determined by current-voltage-temperature (I-V-T) measurements. The interface property of Pd/ Si1−xGex/Si were studied as a function of metal deposition and post annealing temperatures.

Comparative Study of Temperature Dependent Barrier Heights of Pd/ZnO Schottky Diodes Grown along Zn- and O-Faces

2012 ◽  
Vol 510-511 ◽  
pp. 265-270 ◽  
Author(s):  
M. Asghar ◽  
Khalid Mahmood ◽  
Adnan Ali ◽  
M.A. Hasan
Keyword(s):  
Barrier Height ◽  
Deep Level ◽  
Schottky Diodes ◽  
Thermionic Emission ◽  
Growth Conditions ◽  
Distribution Model ◽  
Metal Contacts ◽  
Temperature Dependent ◽  
Barrier Heights ◽  
Two Samples

In this study, the effect of polar face on Schottky barrier diodes has been investigated. Two samples of ZnO were grown hydrothermally under similar growth conditions. The Palladium (Pd) metal contacts of area 0.78 mm2were fabricated on both faces and were studied comprehensively using DLS-83 Deep Level Spectrometer over temperature range of 160K330K. The current-voltage (IV) measurements revealed that the ideality factor n and barrier height ϕBwere strongly temperature dependent for both faces (Zn and O-face) of ZnO, indicating that the thermionic emission is not the dominant process, which showed the inhomogenity in the barrier heights of grown samples. This barrier height inhomogenity was explained by applying Gaussian distribution model. The extrapolation of the linear ϕapverses n plot to n = 1 has given a homogeneous barrier height of approximately 0.88±0.01 eV and 0.76±0.01 eV for Zn and O-faces respectively. ϕapversus 1/T plot was drawn to obtain the values of mean barrier height for Zn and O-face (0.88±0.01 eV, 0.76±0.01 eV) and standard deviation (δs) (0.015±0.001 V, 0.014±0.001 V) at zero bais respectively. The value of δsfor the Zn-face is larger than O-face, showing that inhomogenity in the barrier heights is more in the sample grown along Zn-face as compared to the sample grown along O-face.

Schottky I-V Characteristics of Au/Ni/GaN/SiNx nanonework/sapphire structures

2006 ◽  
Vol 955 ◽  
Author(s):  
Jinqiao Xie ◽  
Yi Fu ◽  
Hadis Morkoç
Keyword(s):  
Vapor Deposition ◽  
Metalorganic Chemical Vapor Deposition ◽  
Schottky Diodes ◽  
Chemical Vapor ◽  
Rocking Curve ◽  
X Ray ◽  
Sapphire Substrates ◽  
Control Samples

ABSTRACTGaN layers on sapphire substrates were grown by metalorganic chemical vapor deposition using in situ porous SiNx nano-network. Crystalline quality of epilayers was characterized by X-ray rocking curve scans, and the full width at hall maximum values for (002) and (102) diffractions were improved from 252 arc sec and 405 arc sec, respectively, in control samples to 216 arc sec and 196 arc sec when SiNx was used. Ni/Au Schottky diodes (SDs) were fabricated and the SD performance was found to be critically dependent on the SiNx coverage (fewer and farther the pores the better the results) which is consistent with the trends of XRD and photoluminescence data. A 1.13eV barrier height was achieved when 5min SiNx layer was used compared with 0.78 eV without any SiNx nanonetwork. Furthermore, the breakdown voltage improved from 76 V to 250V when SiNx nanonetwork was used in otherwise identical structures.

Effect of Mechanical Stress on Polycrystalline Diamond Schottky Diode I-V Characteristics

1992 ◽  
Vol 270 ◽  
Author(s):  
G. Zhao ◽  
E. M. Charlson ◽  
E. J. Charlson ◽  
T. Stacy ◽  
J. Meese ◽  
...  
Keyword(s):  
Mechanical Stress ◽  
Schottky Diodes ◽  
Forward Bias ◽  
Chemical Vapor ◽  
Polycrystalline Diamond ◽  
Deposition Process ◽  
Stress Sensitivity ◽  
Stress Effect ◽  
Mechanical Sensors ◽  
Hot Filament

ABSTRACTSchottky diodes to be used for mechanical stress effect studies were fabricated using aluminum contacts to polycrystalline diamond thin films grown by a hot-filament assisted chemical vapor deposition process. Compressive stress was found to have a large effect on the forward biased current-voltage characteristics of the diode. At selected values of constant forward biased current, a linear relationship between voltage and stress, for stress less than 10 N was observed. The stress sensitivity of the diode was as high as 0.74 V/N at 1 mA forward bias. This study shows that polycrystalline diamond Schottky diodes are stress sensitive devices and have potential as mechanical sensors.

AN ASSESSMENT ON ELECTRICAL CHARACTERIZATION OF Ni/n-Si SCHOTTKY RECTIFIERS WITH AND WITHOUT Ta2O5 INTERFACIAL OXIDE LAYER

2019 ◽  
Vol 26 (10) ◽  
pp. 1950073 ◽  
Author(s):  
N. NANDA KUMAR REDDY ◽  
P. ANANDA ◽  
V. K. VERMA ◽  
K. RAHIM BAKASH
Keyword(s):  
Schottky Barrier ◽  
Oxide Layer ◽  
Barrier Height ◽  
Series Resistance ◽  
Schottky Diodes ◽  
Forward Bias ◽  
Thermionic Emission ◽  
Mis Structure ◽  
Schottky Barrier Diodes ◽  
Mis Structures

We have fabricated Ni/[Formula: see text]-Si metal–semiconductor (MS) and Ni/Ta2O5/[Formula: see text]-Si metal-insulator–semiconductor (MIS) Schottky barrier diodes at room temperature and studied their current density–voltage (J–V) and capacitance–voltage (C–V) characteristic properties. The forward bias J–V characteristics of the fabricated MS and MIS devices have been evaluated with the help of the thermionic emission (TE) mechanism. Schottky barrier height (SBH) values of 0.73 and 0.84[Formula: see text]eV and ideality factor values of 1.75 and 1.46 are extracted using J–V measurements for MS and MIS Schottky barrier diodes without and with Ta2O5 interfacial oxide layer, respectively. It was noted that the incorporation of Ta2O5 interfacial oxide layer enhanced the value of SBH for the MIS device because this oxide layer produced the substantial barrier between Ni and [Formula: see text]-Si and this obtained barrier height value is better than the conventional metal/[Formula: see text]-Si (MS) Schottky diodes. The rectification ratio (RR) calculated at [Formula: see text][Formula: see text]V for the MS structure is found to be [Formula: see text] and the MIS structure is found to be [Formula: see text]. Using Chung’s method, the series resistance ([Formula: see text]) values are calculated using [Formula: see text]/[Formula: see text] vs I plot and are found to be 21,603[Formula: see text][Formula: see text] for the Ni/[Formula: see text]-Si (MS) and 5489[Formula: see text][Formula: see text] for the Ni/Ta2O5/[Formula: see text]-Si (MIS) structures, respectively. In addition, [Formula: see text] vs [Formula: see text] plot has been utilized to evaluate the series resistance ([Formula: see text]) values and are found to be 14,064[Formula: see text][Formula: see text] for the Ni/[Formula: see text]-Si (MS) and 2236[Formula: see text][Formula: see text] for the Ni/Ta2O5/[Formula: see text]-Si (MIS) structures, respectively. In conclusion, by analyzing the experimental results, it is confirmed that the good quality performance is observed in Ni/Ta2O5/[Formula: see text]-Si (MIS) type SBD when compared to Ni/[Formula: see text]-Si (MS) type SBD and can be accredited to the intentionally formed thin Ta2O5 interfacial oxide layer between Nickel and [Formula: see text]-type Si.

Electrical Properties of Schottky Contacts of TiW on RTCVD Si1-x-yGexCy Films

1997 ◽  
Vol 470 ◽  
Author(s):  
Jian Mi ◽  
Yilu Zhang ◽  
Patricia Warren ◽  
Cary Y. Yang
Keyword(s):  
Electrical Properties ◽  
Series Resistance ◽  
Schottky Diodes ◽  
Forward Bias ◽  
Tunneling Current ◽  
Chemical Vapor ◽  
Schottky Contacts ◽  
Crystal Defects ◽  
Recombination Centers ◽  
High Series

ABSTRACTHigh-quality epitaxial Si1-x-yGexCy layers were grown on Si by rapid thermal chemical vapor deposition. Schottky diodes of TiW/SiGeC were fabricated using conventional Si processes. I-V and C-V measurements were performed to assess effects of crystal defects in the alloy on the electrical properties. For defective SiGeC films due to non-substitutional carbon, high series resistance and additional tunneling current were measured under forward bias, as well as leakage current under reverse bias. A transport mechanism of deep generation/recombination centers formed by carbon complexes is proposed to explain the I-V characteristics.

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.

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