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-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.

An Electrical and Physical Study of Crystal Damage in High-Dose Al- and N-Implanted 4H-SiC

2017 ◽  
Vol 897 ◽  
pp. 411-414 ◽  
Author(s):  
Craig A. Fisher ◽  
Romain Esteve ◽  
Stefan Doering ◽  
Michael Roesner ◽  
Martin de Biasio ◽  
...  
Keyword(s):  
High Temperature ◽  
Room Temperature ◽  
High Dose ◽  
Stress Determination ◽  
Analysis Techniques ◽  
Physical Study ◽  
Crystal Damage ◽  
Activation Annealing ◽  
Anneal Temperature ◽  
High Dose Implantation

In this paper, an investigation into the crystal structure of Al-and N-implanted 4H-SiC is presented, encompassing a range of physical and electrical analysis techniques, with the aim of better understanding the material properties after high-dose implantation and activation annealing. Scanning spreading resistance microscopy showed that the use of high temperature implantation yields more uniform resistivity profiles in the implanted layer; this correlates with KOH defect decoration and TEM observations, which show that the crystal damage is much more severe in room temperature implanted samples, regardless of anneal temperature. Finally, stress determination by means of μRaman spectroscopy showed that the high temperature implantation results in lower tensile stress in the implanted layers with respect to the room temperature implantation samples.

Formation of Buried Sio2 By High Dose Implantation of Oxygen at Room and Liquid Nitroeen Temperatures

1985 ◽  
Vol 53 ◽  
Author(s):  
F. Namavar ◽  
J. I. Budnick ◽  
F. H. Sanchez ◽  
H. C. Hayden
Keyword(s):  
Liquid Nitrogen ◽  
Current Density ◽  
Room Temperature ◽  
Rutherford Backscattering ◽  
High Dose ◽  
Crystalline Quartz ◽  
Oxygen Ions ◽  
High Dose Implantation ◽  
A Current

ABSTRACTWe have carried out a study to understand the mechanisms involved in the formation of buried SIO2 by high dose implantation of oxygen into Si targets. Oxygen ions were implanted at 150 keV with doses up to 2.5 X 1018 ions/cm2 and a current density of less than 10 μA/cm2 into Si 〈100〉 at room and liquid nitrogen temperatures. In-situ Rutherford backscattering (RBS) analysis clearly indicates the formation of uniform buried SIO2 for both room and liquid nitrogen temperatures for doses above 1.5 X 1018/cm2.Oxygen ions were implanted at room temperature into crystalline quartz to doses of about 1018 ions cm2 at 150 keV, with a current density of 〈10〉10 μA/cm2. The RBS spectra of the oxygen implanted quartz cannot be distinguished from those of unimplanted ones. Furthermore, Si ions were implanted into crystalline quartz at 80 keV and dose of 1 X 1017 Si/cm2, and a current aensity of about 1 μA/cm2. However, no signal from Si in excess of the SiO2 ratio could be observed. Our results obtained by RBS show that implantation of either Si+ or O into SiO2 under conditions stated above does not create a layer whose Si:O ratio differs measurably from that of SiO2.

Simulation of Transient Enhanced Diffusion in Silicon Taking into Account Ostwald Ripening of Defects

2002 ◽  
Vol 717 ◽  
Author(s):  
Masashi Uematsu
Keyword(s):  
Time Dependence ◽  
Diffusion Model ◽  
Low Dose ◽  
Ostwald Ripening ◽  
High Dose ◽  
Enhanced Diffusion ◽  
Annealing Conditions ◽  
Transient Enhanced Diffusion ◽  
High Dose Implantation ◽  
Medium Dose

AbstractThe transient enhanced diffusion (TED) of high-dose implanted P is simulated taking into account Ostwald ripening of end-of-range (EOR) defects. First, we integrated a basic diffusion model based on the simulation of in-diffusion, where no implanted damages are involved. Second, from low-dose implantation, we developed a model for TED due to {311} self-interstitial (I) clusters involving Ostwald ripening and the dissolution of {311} clusters. Third, from medium-dose implantation, we showed that P-I clusters should be taken into account, and during the diffusion, the clusters are dissolved to emit self-interstitials that also contribute to TED. Finally, from high-dose implantation, EOR defects are modeled and we derived a formula to describe the time-dependence for Ostwald ripening of EOR defects, which is more significant at higher temperatures and longer annealing times. The simulation satisfactorily predicts the TED for annealing conditions, where the calculations overestimate the diffusion without taking Ostwald ripening into account.

Room Temperature Damage, Annealing and Dislocation Growth in Silicon

1994 ◽  
Vol 373 ◽  
Author(s):  
R.G. Elliman ◽  
I.V. Mitchell
Keyword(s):  
Electron Microscopy ◽  
Room Temperature ◽  
Rutherford Backscattering Spectrometry ◽  
Extended Defects ◽  
High Temperature Annealing ◽  
Primary Defect ◽  
Implantation Temperature ◽  
Transmission Electron ◽  
Sensitive Function ◽  
Temperature Damage

AbstractThe concentration of residual defects produced by self ion implantation of silicon has been shown to be a sensitive function of implantation temperature at temperatures near room temperature. In this study samples were heated to temperatures of 20°C and 60°C and implanted with 540 keV Si ions to a fluence of 2x1015Si.cm-2 using a constant scanned ion flux of 0.2 μA.cm-2. The resultant primary defect concentrations, measured by Rutherford backscattering spectrometry and channelling (RBS-C), were 2.3±0.1x1022 cm-l and 1.8±0.2x1021 cm-3, respectively, i.e. a reduction by a factor of σ13 for a temperature increase of 40°C. Such differences were not evident in the concentration of secondary defects formed by annealing these samples at 900°C for 15 minutes: the defect concentrations were equal within the experimental uncertainties of the RBS-C and transmission electron microscopy (TEM) measurements. This result appears to lead to the surprising conclusion that the number of displaced atoms that survive high temperature annealing to form extended defects is largely independent of the dynamic annealing processes operating during implantation but depends instead on parameters which scale with the ion fluence.

Effects of implantation temperature on the structure, composition, and oxidation resistance of aluminum-implanted SiC

1995 ◽  
Vol 10 (6) ◽  
pp. 1441-1447 ◽  
Author(s):  
Zunde Yang ◽  
Honghua Du ◽  
Matthew Libera ◽  
Irwin L. Singer
Keyword(s):  
Oxidation Resistance ◽  
Room Temperature ◽  
Aluminum Carbide ◽  
High Dose ◽  
Optimum Range ◽  
Implantation Temperature ◽  
Transmission Electron ◽  
Oxidation Layers ◽  
Flowing Oxygen ◽  
High Aluminum

α-SiC crystals were implanted with aluminum to a high dose at room temperature or 800 °C. Transmission electron microscopy showed that SiC was amorphized by room temperature implantation but remained crystalline after 800 °C implantation. Crystalline aluminum carbide was formed and aluminum redistribution took place in SiC implanted at 800 °C. Implanted and unimplanted crystals were oxidized in 1 atm flowing oxygen at 1300 °C. Amorphization led to accelerated oxidation of SiC. The oxidation resistance of SiC implanted at 800 °C was comparable with that of pure SiC. The oxidation layers formed on SiC implanted at both temperatures consisted of silica embedded with mullite precipitates. The phase formation during implantation and oxidation is consistent with thermodynamic predictions. The results from our current and earlier studies suggest that there exists an optimum range of implantation temperature, probably above 500 °C but below 800 °C, which preserves the substrate crystallinity and retains the high aluminum dosage, for the enhancement of oxidation resistance of SiC.

Photoluminescence of Ge Nanoclusters in Ion Implanted SiO2

2002 ◽  
Vol 744 ◽  
Author(s):  
J.M.J. Lopes ◽  
F.C. Zawislak ◽  
M. Behar ◽  
P.F.P. Fichtner ◽  
L. Rebohle ◽  
...  
Keyword(s):  
Room Temperature ◽  
Depth Distribution ◽  
Rutherford Backscattering Spectrometry ◽  
Ultra Violet ◽  
Room Temperature Photoluminescence ◽  
Transmission Electron ◽  
Coarsening Behavior ◽  
The Mean ◽  
Luminescent Centers ◽  
Post Implantation

ABSTRACT180 nm thick SiO2 films produced by wet oxidation of (100) Si wafers were implanted at room temperature with 120 keV Ge+ ions at a fluence of 1.2×10 cm-2 in order to allow the formation of Ge nanoparticles upon post implantation thermal annealings within the interval 400°C ≤ T ≤ 900°C. The size and depth distribution of the Ge nanoparticles were characterized by Transmission Electron Microscopy and Rutherford Backscattering Spectrometry. In addition, the room temperature photoluminescence (PL) bands of the nanoparticles system were studied in the regions of the blue-violet and ultra-violet emissions. The mean diameter of the nanoclusters increases from 2.2 nm at 400°C to 5.6 nm at 900°C. Concomitantly, the blue-violet PL intensity increases by a factor of 12 within the same temperature interval. The results are discussed in terms of possible atomic mechanisms involved in the coarsening behavior and leading to the formation of luminescent centers.

Effects of Implantation Temperature on the Structure, Composition and Oxidation Resistance of Sic

1994 ◽  
Vol 354 ◽  
Author(s):  
Zunde Yang ◽  
Honghua Du ◽  
Matthew Libera ◽  
Irwin L. Singer
Keyword(s):  
Electron Microscopy ◽  
Oxidation Resistance ◽  
Room Temperature ◽  
Aluminum Carbide ◽  
High Dose ◽  
Accelerated Oxidation ◽  
Implantation Temperature ◽  
Transmission Electron ◽  
Oxidation Layers ◽  
Flowing Oxygen

Abstractɑ-SiC crystals were implanted with aluminum to a high dose at room temperature or 800°C. Studies by transmission electron microscopy showed that SiC was amorphized by room temperature implantation but remained crystalline at 800°C. Crystalline aluminum carbide was formed and aluminum redistribution took place in SiC implanted at 800°C. Implanted and unimplanted crystals were oxidized in 1 atm flowing oxygen at 1300°C. Amorphization led to accelerated oxidation of SiC. The oxidation resistance of SiC implanted at 800°C was comparable to that of pure SiC. The oxidation layers formed on SiC implanted at both temperatures consisted of silica embedded with mullite precipitates. The phase formation during implantation and oxidation is consistent with thermodynamic predictions.

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.

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