Ion Beam Synthesis By Tungsten Implantation Into 6h-Silicon Carbide At Elevated Temperatures

1996 ◽  
Vol 423 ◽  
Author(s):  
Hannes Weishart ◽  
W. Matz ◽  
W. Skorupa
Keyword(s):  
Silicon Carbide ◽  
Tungsten Carbide ◽  
Elevated Temperatures ◽  
Rutherford Backscattering Spectrometry ◽  
Ion Beam ◽  
Bimodal Distribution ◽  
High Dose ◽  
Electrically Conductive ◽  
Implantation Temperature ◽  
High Dose Implantation

AbstractWe studied high dose implantation of tungsten into 6H-silicon carbide in order to synthesize an electrically conductive layer. Implantation was performed at 200 keV with a dose of 1×1017 W+cm−2 at temperatures of 90°C and 500°C. The samples were subsequently annealed either at 950°C or 1100°C. The influence of implantation and annealing temperatures on the reaction of W with SiC was investigated. Rutherford backscattering spectrometry (RBS), x-ray diffiraction (XRD) and Auger electron spectroscopy (AES) contributed to study the structure and composition of the implanted layer as well as the chemical state of the elements. The implantation temperature influences the depth distribution of C, Si and W as well as the damage production in SiC. The W depth profile exhibits a bimodal distribution for high temperature implantation and a customary gaussian distribution for room temperature implantation. Formation of tungsten carbide and silicide was observed in each sample already in the as-implanted state. Implantation at 90°C and annealing at 950°C lead to crystallization of W2C; tungsten silicide, however, remains amorphous. After implantation at 500°C and subsequent annealing at 11007deg;C crystalline W5Si3 forms, while tungsten carbide is amorphous.

Conductive Tungsten-Based Layers Synthesized by Ion Implantation into 6H-Silicon Carbide

1996 ◽  
Vol 438 ◽  
Author(s):  
H. Weishart ◽  
J. Schoneich ◽  
M. Voelskow ◽  
W. Skorupa
Keyword(s):  
Silicon Carbide ◽  
Room Temperature ◽  
Depth Distribution ◽  
Ostwald Ripening ◽  
Rutherford Backscattering Spectrometry ◽  
High Dose ◽  
Electrically Conductive ◽  
Gaussian Shape ◽  
Implantation Temperature ◽  
High Dose Implantation

AbstractWe studied high dose implantation of tungsten into 6H-silicon carbide in order to synthesize an electrically conductive layer. Implantation was performed at 200 keV with a dose of 1.2x 1017 WIcm 2 at temperatures between 200°C and 400°C. The influence of implantation temperature on the distribution of W in SiC was investigated and compared to results obtained earlier from room temperature (RT) and 500°C implants. Rutherford backscattering spectrometry (RBS) was employed to study the structure and composition of the implanted layers. Implantation at temperatures between RT and 300°C did not influence the depth distribution of C, Si and W. The W depth profile shows a conventional Gaussian shape. Implanting at higher temperatures led to a more confined W rich layer in the SiC. This confinement is explained by Ostwald ripening which is enabled during implantation at temperatures above 300°C. The depth of the implantation induced damage decreases slightly with increasing implantation temperature, except for 400°C implantation. The amount of damage, however, is significantly reduced only for implantation at 500°C.

Conductive Tungsten-Based Layers Synthesized by Ion Implantation Into 6H-Silicon Carbide

1996 ◽  
Vol 439 ◽  
Author(s):  
H. Weishart ◽  
J. schöneich ◽  
M. Voelskow ◽  
W. Skorupa
Keyword(s):  
Silicon Carbide ◽  
Room Temperature ◽  
Depth Distribution ◽  
Ostwald Ripening ◽  
Rutherford Backscattering Spectrometry ◽  
High Dose ◽  
Electrically Conductive ◽  
Gaussian Shape ◽  
Implantation Temperature ◽  
High Dose Implantation

AbstractWe studied high dose implantation of tungsten into 6H-silicon carbide in order to synthesize an electrically conductive layer. Implantation was performed at 200 keV with a dose of 1.2×1017 W+cm−2 at temperatures between 200°C and 400°C. The influence of implantation temperature on the distribution of W in SiC was investigated and compared to results obtained earlier from room temperature (RT) and 500°C implants. Rutherford backscattering spectrometry (RBS) was employed to study the structure and composition of the implanted layers. Implantation at temperatures between RT and 300°C did not influence the depth distribution of C, Si and W. The W depth profile shows a conventional Gaussian shape. Implanting at higher temperatures led to a more confined W rich layer in the SiC. This confinement is explained by Ostwald ripening which is enabled during implantation at temperatures above 300°C. The depth of the implantation induced damage decreases slightly with increasing implantation temperature, except for 400°C implantation. The amount of damage, however, is significantly reduced only for implantation at 500°C.

Ion Beam Synthesis by Tungsten-Implantation Into 6H-SIC

1994 ◽  
Vol 354 ◽  
Author(s):  
Hannes Weishart ◽  
J. Schöneich ◽  
H. J. Steffen ◽  
W. Matz ◽  
W. Skorupa
Keyword(s):  
Tungsten Carbide ◽  
Annealing Temperature ◽  
Rutherford Backscattering Spectrometry ◽  
Ion Beam ◽  
High Dose ◽  
X Ray Diffraction ◽  
X Ray ◽  
Conductive Surface ◽  
Chemical States ◽  
High Dose Implantation

AbstractWe studied high-dose implantation of tungsten into 6H-silicon carbide in order to synthesize a highly conductive surface layer. Implantation was performed at 200 keV at room temperature. Subsequently, the samples were annealed in two steps at 500°C and 700°C or 950°C, respectively. The influence of dose and annealing temperature on the reaction of W with SiC was investigated. Rutherford Backscattering Spectrometry (RBS), X-Ray Diffraction (XRD) and Auger Electron Spectroscopy (AES) contributed to study structure and composition of the layer as well as chemical states of the elements. During implantation sputtering became significant at a dose exceeding 1.0×1017 W+cm−2. Formation of tungsten carbide and suicide was observed already in the as-implanted state. An annealing temperature of 950°C was necessary to crystallize tungsten carbide. However, tungsten suicide remained amorphous at this temperature. Therefore, a mixture of polycrystalline tungsten carbide and amorphous tungsten suicide evolved under these conditions. The resistivity of such a layer implanted with 1.0×1017 W+ cm−2 and annealed at 950°C is 565 μΩcm.

Time Evolution of Nanoscale Surface Topography of Tungsten Carbide Coatings on “Hot” Silicon Carbide Electronics Devices

2007 ◽  
Vol 990 ◽  
Author(s):  
Claudin Muntele ◽  
Daniel Walker ◽  
Abdalla Elsamadicy ◽  
Daryush Ila
Keyword(s):  
Silicon Carbide ◽  
Surface Morphology ◽  
Tungsten Carbide ◽  
Time Evolution ◽  
Elevated Temperatures ◽  
Rutherford Backscattering Spectrometry ◽  
Electrical Contacts ◽  
Current Status ◽  
Force Microscopy ◽  
Carbide Coatings

ABSTRACTWe are reporting here on the current status of our investigations on the time evolution of nanoscale surface morphology of thermally evaporated tungsten carbide coatings on silicon carbide substrates. The purpose of the study is to develop a recipe for creating thermally and chemically stable electrical contacts on silicon carbide electronic devices able to work at elevated temperatures (up to 800 °C) in oxidizing environments. We used thermal evaporation and tungsten carbide (WC) powder as a starting material to produce the thin layer deposition on semi-insulating silicon carbide (6H). Our intended applications are for devices working at 800 °C; therefore, our investigations are carried out at 1 hr intervals of time the samples spent at this temperature, in air at atmospheric pressure. We used Rutherford Backscattering Spectrometry (RBS) for measuring the stoichiometry and depth profile, and Atomic Force Microscopy (AFM) to monitor the surface morphology change.

SiC Precipitate Formation During High Dose Carbon Implantation Into Silicon

1996 ◽  
Vol 439 ◽  
Author(s):  
J. K. N. Lindner ◽  
K. Volz ◽  
B. Stritzker
Keyword(s):  
Density Distribution ◽  
Crystalline Silicon ◽  
Ion Beam ◽  
Host Lattice ◽  
High Dose ◽  
Carbon Ions ◽  
Precipitate Formation ◽  
Ion Beam Synthesis ◽  
High Dose Implantation ◽  
Precipitate Density

AbstractThe formation of SiC precipitates during the high-dose implantation of carbon ions into Si(100) is studied by means of TEM for implantation conditions, which are suitable for the ion beam synthesis of buried SiC layers in silicon. It is observed that in crystalline silicon nm-sized epitaxially oriented 3C-SiC precipitates are formed which are almost identical in size, nearly independent of the depth and dose (4 – 9 ×1017 C+/cm2). With increasing dose, it is mainly the density of precipitates which increases. Amorphization of the silicon host lattice leads to depth intervals with a strongly decreased density of oriented crystalline SiC precipitates. The irradiation induced formation of larger randomly oriented SiC crystallites is observed to occur in amorphized regions after prolonged implantation. Both the irradiation induced destruction and formation of SiC precipitates contribute to the generation of a nearly box-shaped precipitate density distribution at doses near the stoichiometry dose.

Ion Implantation of KnbO3 and LiNbO3 at Elevated Temperatures

1988 ◽  
Vol 128 ◽  
Author(s):  
C H. Buchal ◽  
R. Irmscher ◽  
P. Günter
Keyword(s):  
Ion Implantation ◽  
Dynamic Recrystallization ◽  
Substrate Temperature ◽  
Elevated Temperatures ◽  
High Dose ◽  
Single Crystalline ◽  
First Time ◽  
High Dose Implantation

ABSTRACTIon implantation, annealing and channeling of single crystalline samples of KnbO3 and LiNbO3 have been studied. Raising the substrate temperature above 600 K, greatly increases the tolerance of the crystals for high-dose implantation. In LiNbO3 dynamic recrystallization has been observed for the first time.

Ion beam assisted film growth by high dose implantation of carbon into a liquid medium

1996 ◽  
Vol 278 (1-2) ◽  
pp. 87-95
Author(s):  
R.R. Manory ◽  
R. Sahagian ◽  
S.N. Bunker ◽  
A.J. Armini
Keyword(s):  
Liquid Medium ◽  
Film Growth ◽  
Ion Beam ◽  
High Dose ◽  
High Dose Implantation

Evolution of Defect and Impurity Profile During High Dose Co Implantation into Si at Elevated Temperatures

1993 ◽  
Vol 320 ◽  
Author(s):  
S. Schippel ◽  
A. Witzmann
Keyword(s):  
Point Defects ◽  
Elevated Temperatures ◽  
Rutherford Backscattering Spectrometry ◽  
High Dose ◽  
Impurity Profile ◽  
Gaussian Shape ◽  
Near Surface ◽  
Gaussian Distributions ◽  
Transmission Electron ◽  
Effective Center

ABSTRACT<111> -Si was implanted with 250 keV Co ions at a target temperature of 350°C. The ion dose was varied between 1 × 1014 cm−2 and 2 × 1017 cm−2. The evolution of the defect and impurity profile was investigated by Rutherford Backscattering Spectrometry (RBS), channeling and transmission electron microscopy (TEM).Up to a dose of 1 × 1015 Co cm−2 no defects can be detected. At higher Co doses, we find correlated defects in the center of the Co distribution and point defects in the region below. Moreover, damage accumulation at the surface is observed. The concentration of defects increases with increasing ion dose and reaches its level of saturation at a dose of 2 × 1016 cm−2.The Co profiles of samples implanted at 350°C differ considerably from the Gaussian shape. The near surface and the back flank are parts of Gaussian distributions. However, the standard deviation of the near surface flank is always smaller than that of the back flank. Moreover, the distributions show tails into the substrate at depths > 320 nm. This proves that radiation damage acts as an effective center for the nucleation of CoSi2.During annealing we find a redistribution of Co towards the defective regions for Co doses between 1 × 1016 cm−2 and 5 × 1016 cm−2.

scholarly journals Ion Beam Modification of the Y-Ba-Cu-O System with the Mevva High Current Metal Ion Source

1989 ◽  
Vol 147 ◽  
Author(s):  
I. G. Brown ◽  
M. D. Rubin ◽  
K. M. Yu ◽  
R. Mutikainen ◽  
N. W. Cheung
Keyword(s):  
Ion Implantation ◽  
Metal Ion ◽  
Rutherford Backscattering Spectrometry ◽  
Ion Beam ◽  
Rf Sputtering ◽  
Ion Source ◽  
Vacuum Arc ◽  
High Dose ◽  
High Current ◽  
Ion Beam Modification

AbstractWe have used high-dose metal ion implantation to ‘fine tune’ the composition of Y-Ba- Cu-O thin films. The films were prepared by either of two rf sputtering systems. One system uses three modified Varian S-guns capable of sputtering various metal powder targets; the other uses reactive rf magnetron sputtering from a single mixed-oxide stoichiometric solid target. Film thickness was typically in the range 2000–5000 A. Substrates of magnesium oxide, zirconia-buffered silicon, and strontium titanate have been used. Ion implantation was carried out using a metal vapor vacuum arc (MEVVA) high current metal ion source. Beam energy was 100–200 keV, average beam current about 1 mA, and dose up to about 1017 ions/cm2. Samples were annealed at 800 – 900°C in wet oxygen. Film composition was determined using Rutherford Backscattering Spectrometry (RBS), and the resistivity versus temperature curves were obtained using a four-point probe method. We find that the zero-resistance temperature can be greatly increased after implantation and reannealing, and that the ion beam modification technique described here provides a powerful means for optimizing the thin film superconducting properties.

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