Phase Inhomogeneity and Electrical Characteristics of Nickel Silicide Schottky Contacts Formed on 4H-SiC

2009 ◽  
Vol 615-617 ◽  
pp. 577-580 ◽  
Author(s):  
Irina P. Nikitina ◽  
Konstantin Vassilevski ◽  
Alton B. Horsfall ◽  
Nicolas G. Wright ◽  
Anthony G. O'Neill ◽  
...  
Keyword(s):  
Nickel Silicide ◽  
Schottky Contacts ◽  
Electrical Characteristics ◽  
Adhesion Layer ◽  
Temperature Range ◽  
Barrier Heights ◽  
Phase Inhomogeneity ◽  
Layer 4 ◽  
State Chemical ◽  
Nisi Phase

Nickel silicide Schottky contacts were formed on 4H-SiC by consecutive deposition of a titanium adhesion layer, 4 nm thick, and nickel, 100 nm thick, followed by annealing at temperatures from 600 to 750 °C. It was found that contacts with barrier heights of 1.45 eV, consisting mainly of NiSi phase, formed in the 600-660 °C temperature range, while annealing at around 750 °C led to the formation of Ni2Si phase with barrier heights of 1.1 eV. Annealing at intermediate temperatures resulted in the nucleation of Ni2Si grains embedded in the NiSi film which were directly observed by micro-Raman mapping. It was concluded that the thermodynamically unfavourable NiSi phase appeared in the 600-660 °C temperature range due to the fact that the solid state chemical reaction between Ni and SiC at these temperatures is controlled by nickel diffusion through the titanium barrier.

The Study of TiWN Schottky Contacts on n-Ga0.51 In0.49P

1993 ◽  
Vol 300 ◽  
Author(s):  
Edward Y. Chang ◽  
Yeong-Lin Lai ◽  
Kuen-Chyuan Lin ◽  
Chun-Yen Chang ◽  
F. Y. Juang
Keyword(s):  
Schottky Contact ◽  
Rf Magnetron Sputtering ◽  
Schottky Contacts ◽  
Electrical Characteristics ◽  
X Ray Diffraction ◽  
Barrier Heights ◽  
Annealing Conditions ◽  
Transmission Electron ◽  
Lattice Matched ◽  
Thermal Stability Of

ABSTRACTThe first study of the TiW nitrides (TiWNx) as the Schottky contact metals to the n type Ga0.51In0 49P has been made. The Ga0.51 In0.49P epitaxial layer was successfully grown on the GaAs substrate by LP-MOCVD to form a lattice-matched heterostructure. The RF-magnetron sputtering system was utilized for the nitride deposition. The thermal stability of the nitride films were studied using rapid thermal annealing (RTA) method. Both the electrical characteristics and the materials characteristics were investigated. The materials properties of the nitride films were characterized by X-ray diffraction (XRD), Transmission electron microscopy (TEM), and Auger electron spectroscopy (AES). The TiWNx Schottky contacts demonstrate excellent electrical and physical characteristics, even after high temperature annealing. The barrier heights range from 0.81 to 1.05 eV depending on the content of the nitrogen and the annealing conditions. The XRD and AES results show no indication of interaction at the TiWNX/GaInP interface of both as-deposited and annealed samples. The outstanding characteristics of the contact were attributed to the high bandgap nature of the Ga0.51In0.49P and the incorporation of nitrogen into the TiW films.

scholarly journals Nickel silicide formation with rapid thermal treatment in the heat balance mode

2021 ◽  
Vol 65 (1) ◽  
pp. 111-118
Author(s):  
V. A. Pilipenko ◽  
Ja. A. Solovjov ◽  
P. I. Gaiduk
Keyword(s):  
Thermal Treatment ◽  
Heat Balance ◽  
Nickel Silicide ◽  
Treatment Temperature ◽  
Specific Resistivity ◽  
Thermal Treatment Temperature ◽  
Temperature Range ◽  
Average Grain Size ◽  
Nisi Phase ◽  
The Heat Balance

The formation of nickel silicide layers on (111)-Si substrates during rapid thermal annealing in the heat balance mode was studied by the Rutherford backscattering method, X-ray diffraction, transmission electron microscopy, and electrophysical measurements. Nickel films of about 70 nm thickness were deposited by magnetron sputtering at room temperature. The rapid thermal treatment was carried out in a heat balance mode by irradiating the substrates backside with a non-coherent light flux of quartz halogen lamps in the nitrogen medium for 7 seconds up to the temperature range of 200 to 550 °C. The redistribution of nickel and silicon atoms to monosilicide NiSi composition starts already at a temperature of 300 °С and almost ends at a temperature of 400 °С. In the same temperature range, the orthorhombic NiSi phase with an average grain size of about 0.05–0.1 μm is formed. At a rapid thermal treatment temperature of 300 °C, two phases of silicides (Ni2 Si and NiSi) are formed, while a thin layer of unreacted Ni is retained on the surface. This fact can be explained by the high heating rate at the initial annealing stage, at which the temperature conditions of the NiSi phase formation occur earlier than the entire Ni layer manages to turn into the Ni2 Si phase. The layers with a simultaneous presence of three phases are characterized by a high roughness of the silicide-silicon interface. The dependence of the specific resistivity of nickel silicide layers shows an increase to the values of 26–30 μOhm · cm in the range of rapid thermal treatment temperatures of 200–250 °C and a subsequent decrease to the values of about 15 μOhm · cm at a rapid thermal treatment temperature of 400 °C. This value of specific resistivity is characteristic of the high conductivity of the NiSi phase and correlates well with the results of structure studies.

Metallurgical and Electrical Characteristics of MoAlx Schottky Contacts to n-GaAs

1992 ◽  
Vol 260 ◽  
Author(s):  
T. S. Huang ◽  
J. G. Peng ◽  
C. C. Lin
Keyword(s):  
Thermal Processing ◽  
Annealing Temperature ◽  
Schottky Diodes ◽  
Schottky Contacts ◽  
Electrical Characteristics ◽  
Interfacial Stability ◽  
X Ray Diffraction ◽  
X Ray ◽  
Barrier Heights ◽  
Current Voltage

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.

Phase composition and electrical characteristics of nickel silicide Schottky contacts formed on 4H–SiC

2009 ◽  
Vol 24 (5) ◽  
pp. 055006 ◽  
Author(s):  
I Nikitina ◽  
K Vassilevski ◽  
A Horsfall ◽  
N Wright ◽  
A G O'Neill ◽  
...  
Keyword(s):  
Phase Composition ◽  
Nickel Silicide ◽  
Schottky Contacts ◽  
Electrical Characteristics

Comparison of Electrical Characteristics of 4H-SiC(0001) and (000-1) Schottky Barrier Diodes

2006 ◽  
Vol 527-529 ◽  
pp. 927-930 ◽  
Author(s):  
Tomonori Nakamura ◽  
Toshiyuki Miyanagi ◽  
Isaho Kamata ◽  
Hidekazu Tsuchida
Keyword(s):  
Schottky Barrier ◽  
Annealing Temperature ◽  
Schottky Contact ◽  
Schottky Contacts ◽  
Electrical Characteristics ◽  
Schottky Barrier Diodes ◽  
Barrier Heights ◽  
Excess Current ◽  
Low Leakage ◽  
Low Leakage Current

We compared the electrical characteristics of 4H-SiC(0001) and (000-1) Schottky barrier diodes (SBDs), and derived the Schottky barrier heights (Hbs) of Ta, W, Mo, and Pd on {0001}. We investigated the annealing temperature dependence of Hbs in Mo and the W Schottky contacts for (0001) and (000-1). The Hbs are increased by annealing, except for the W Schottky contact on (0001). The yields of 0.25 cm2 as-deposited Mo-SBDs were 93.3% for (0001) and 71.1% for (000-1), respectively. We also demonstrated over 1 cm2 (0001) as-deposited Mo-SBD with a low leakage current, an excellent ideality factor, and no excess current, encouraging the enlargement of the active area in the SBD.

Effect of Thermal Treatment for Pd and PdSi Schottky Contacts on p-GaN

2006 ◽  
Vol 517 ◽  
pp. 242-246
Author(s):  
C.K. Tan ◽  
Azlan Abdul Aziz ◽  
F.K. Yam ◽  
C.W. Lim ◽  
Hassan Zainuriah ◽  
...  
Keyword(s):  
Thermal Treatment ◽  
Schottky Barrier ◽  
Leakage Current ◽  
Schottky Diode ◽  
Schottky Diodes ◽  
Schottky Contacts ◽  
Electrical Characteristics ◽  
Barrier Heights

Pd Schottky diode exhibited stable rectifying behavior up to 500°C for 35 minutes in sequential annealing; with the Schottky barrier heights (SBHs), ΦB (I-V) of 0.6-0.7eV with the leakage current (LC) of 20 A at -5V. With the same range of SBHs, PdSi diodes were stable up to 500°C for 5 minutes with the LC of 0.182mA at -5V. The electrical characteristics obtained in this study are also compared with those obtained for Pd and PdSi Schottky diodes on p-GaN.

Temperature-Dependent Electrical Characteristics of Ag Schottky Contacts to Differently Grown O-Polar Bulk ZnO

2013 ◽  
Vol 135 (1) ◽  
Author(s):  
Hogyoung Kim ◽  
Ahrum Sohn ◽  
Yunae Cho ◽  
Dong-Wook Kim
Keyword(s):  
Electron Transport ◽  
Electrical Properties ◽  
Schottky Contact ◽  
Thermionic Emission ◽  
Schottky Contacts ◽  
Current Transport ◽  
Electrical Characteristics ◽  
Temperature Dependent ◽  
Barrier Heights ◽  
Two Samples

The temperature-dependent electrical properties of Ag Schottky contacts to differently grown O-polar bulk ZnO single crystals were comparatively investigated in the temperature range of 100–300 K. Schottky contact to hydrothermal ZnO produced the higher barrier heights (lower ideality factors) than that of pressurized melt-grown ZnO. The modified Richardson plots for two samples produced the larger Richardson constant compared to the theoretical value of 32 A cm−2 K−2 for n-type ZnO, indicating that the inhomogeneous barrier height with the thermionic emission (TE) model could not explain the current transport. The conductive accumulation layers on the ZnO surfaces might not be removed effectively for two samples, which degraded the rectifying characteristics. The different electron transport characteristics between hydrothermal and pressurized melt-grown ZnO could be explained by the different degree of Ag-O formation at the interface.

High Temperature Operation of Silicon Carbide Schottky Diodes with Recoverable Avalanche Breakdown

2006 ◽  
Vol 527-529 ◽  
pp. 931-934 ◽  
Author(s):  
Konstantin Vassilevski ◽  
Irina P. Nikitina ◽  
Praneet Bhatnagar ◽  
Alton B. Horsfall ◽  
Nicolas G. Wright ◽  
...  
Keyword(s):  
Room Temperature ◽  
Schottky Diodes ◽  
Nickel Silicide ◽  
Schottky Contacts ◽  
Avalanche Breakdown ◽  
Positive Temperature ◽  
Barrier Heights ◽  
Boron Implantation ◽  
High Temperature Operation ◽  
The Ideal

4H-SiC diodes with nickel silicide (Ni2Si) and molybdenum (Mo) Schottky contacts have been fabricated and characterised at temperature up to 400°C. Room temperature boron implantation has been used to form a single zone junction termination extension. Both Ni2Si and Mo diodes revealed unchanging ideality factors and barrier heights (1.45 and 1.3 eV, respectively) at temperatures up to 400°C. Soft recoverable breakdowns were observed both in Ni2Si and Mo Schottky diodes at voltages above 1450 V and 3400 V depending on the epitaxial structure used. These values are about 76% and 94% of the ideal avalanche breakdown voltages. The Ni2Si diodes revealed positive temperature coefficients of breakdown voltage at temperature up to 240°C.

Microstructure studies of tungsten silicide schottky contacts on Gaas

1987 ◽  
Vol 45 ◽  
pp. 328-329
Author(s):  
Yih-Cheng Shih ◽  
E. L. Wilkie
Keyword(s):  
Thermal Stability ◽  
Field Effect Transistors ◽  
Schottky Contact ◽  
Schottky Contacts ◽  
Excellent Thermal Stability ◽  
Barrier Heights ◽  
Gaas Substrates ◽  
Film Adhesion ◽  
Threshold Voltages ◽  
Thermal Stability Of

Tungsten silicides (WSix) have been successfully used as the gate materials in self-aligned GaAs metal-semiconductor-field- effect transistors (MESFET). Thermal stability of the WSix/GaAs Schottky contact is of major concern since the n+ implanted source/drain regions must be annealed at high temperatures (∼ 800°C). WSi0.6 was considered the best composition to achieve good device performance due to its low stress and excellent thermal stability of the WSix/GaAs interface. The film adhesion and the uniformity in barrier heights and ideality factors of the WSi0.6 films have been improved by depositing a thin layer of pure W as the first layer on GaAs prior to WSi0.6 deposition. Recently WSi0.1 has been used successfully as the gate material in 1x10 μm GaAs FET's on the GaAs substrates which were sputter-cleaned prior to deposition. These GaAs FET's exhibited uniform threshold voltages across a 51 mm wafer with good film adhesion after annealing at 800°C for 10 min.

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