The Experts below are selected from a list of 312 Experts worldwide ranked by ideXlab platform
B.s. Satyanarayana - One of the best experts on this subject based on the ideXlab platform.
-
Effect of electron irradiation on morphological, compositional and electrical properties of nanocluster carbon thin films grown using room temperature based cathodic Arc Process for large area microelectronics
Microelectronics Reliability, 2014Co-Authors: Shounak De, B.s. Satyanarayana, Ganesh Sanjeev, K. Ramakrishna, Manjunatha PattabiAbstract:Abstract The influence of 8 MeV electron beam bombardment on room temperature grown nanocluster carbon using cathodic Arc Process has been studied here. Atomic force microscopy (AFM) study shows that surface roughness varies with varying electron doses. High doses of electrons could causes thermal induce graphitization and morphological changes in the films. Raman spectroscopy analysis reveals that G-peak vary from 1555 cm−1 to 1570 cm−1 and D-peak varying from 1361 cm−1 to 1365 cm−1 indicating the disorderness and presence of both graphitic and diamond-like phases. Room temperature conductivity changes by two to three orders in magnitude. The conductivity in the films could be due to conduction of charge carriers through neighboring islands of conductive chains. Defect states calculated using the differential technique varies from 8 × 1017cm−3 eV−1 to 1.5 × 1019 cm−3 eV−1. Irradiation of nanocluster carbon thin films could be helpful to tune the electrical properties and defect densities of the nanocluster carbon films for various large area, flexible electronic and nano electronic applications.
-
Fourier-transform infrared absorption study of the nanocluster carbon thin films grown using cathodic Arc Process
2011Co-Authors: Shounak De, B.s. Satyanarayana, Shailesh SharmaAbstract:Nanocluster carbon thin films are deposited on Silicon Substrate using Cathodic Arc Process. These films are mixed phased materials containing both sp2 and sp3 bondings. The surface morphology is characterized by Fourier‐Transform Infrared Spectroscopy (FTIR) to find out different vibrational modes in these films. The various bendings modes with Olefinic and aromatic structures are associated with a broad absorption band between 1130 and 1550 cm−1. The peaks in and around 2900 cm−1 shows various stretching modes of C‐Hn (n = 1,2,3).
-
Raman spectroscopy and conductivity variation of nanocluster carbon thin films grown using a room temperature based cathodic Arc Process
Scientia Iranica, 2011Co-Authors: Shounak De, S. Niranjana, B.s. SatyanarayanaAbstract:Nanocluster Carbon (NC) thin films grown at room temperature, using a cathodic Arc Process, under varying deposition conditions, exhibit interesting electrical and opto-electronic properties. These films are mixed phase material containing both sp2 (graphite-like) and sp3 (diamond-like) bonding. A Raman G-peak has been observed between 1585 and 1595 cm−1, which indicates graphite-like bonding. A Raman D-peak has been observed between 1355 and 1365 cm−1, which indicates disorderliness in the carbon structure of the films. The Raman spectra of the films were deconvoluted using Breit–Wigner–Fano line shapes. The Raman parameters, including intensity ratios, peak positions, Full-Width Half Maxima (FWHM) and coupling coefficients obtained from both line shapes, were described and compared with varying Helium partial pressures. The dependence on temperature of the conductivity, showing two regions of electronic transport, is explained based on a thermal-assisted tunneling Process. The electrical conductivity varies from 1×10−4 S/cm to 1.66×10−5 S/cm with respect to varying deposition parameters, such as Arc current, DC bias and throw distance.
-
A comparison study of field assisted electron emission from nanocluster carbon films grown using a continuous and a pulsed cathodic Arc Process
2005 International Vacuum Nanoelectronics Conference, 2005Co-Authors: B.s. SatyanarayanaAbstract:Field emission from nanoclustered carbon films grown using pulsed cathodic Arc Process is presented and compared with carbon films grown using continuous cathodic Arc Process. The samples exhibit relatively low field electron emission. However, films grown using pulsed Arc Process show slightly higher emission threshold compared to those grown using continuous cathodic Arc Process. This may be attributed to the difference in the energy kinetics of the Arc initiation Process. Raman measurements also show that films grown using continuous Arc have better clusters and less amorphous phase leading to relatively more distinct G and D peaks compared to the broader G peak and shoulder indicating the D peak observed for films grown using a trigger less pulsed Arc.
-
Characterization of as grown and nitrogen incorporated tetrahedral amorphous carbon films deposited by pulsed unfiltered cathodic vacuum Arc Process
Thin Solid Films, 2005Co-Authors: O.s. Panwar, B.s. Satyanarayana, Mohd Alim Khan, R. BhattacharyyaAbstract:Reported is a study of the as grown and nitrogen incorporated tetrahedral amorphous carbon (ta-C) films deposited by a pulsed unfiltered cathodic vacuum Arc Process using Raman scattering, photoluminescence (PL) and Fourier transform infrared (FTIR) spectroscopy. The influence of the substrate bias in as grown ta-C films and the effect of the nitrogen content in nitrogen incorporated ta-C films under a fixed bias condition were studied. The Raman spectroscopic study showed that, in the present study, the as grown ta-C films deposited at 40 V substrate bias possibly have the highest sp3 bonded carbon concentration, as observed by the large shift in the G peak to ∼1596 cm−1. In the case of the nitrogen incorporated ta-C films, the G peak exhibited a shift towards lower wave number with increasing nitrogen content, suggesting an increase in disorder. The PL spectra indicated a strong peak ∼2.21 eV arising due to extended defects like dislocations followed by a small one ∼1.92 eV which could be identified as a zero phonon line (ZPL) doublet. Another peak at ∼2.63 eV could be attributed to TR12 center. PL peak at ∼2.21 eV showed an inflexion in ta-C films deposited at 40 V substrate bias. An increase in intensity of the PL peak at ∼2.17 eV and its full width at half maximum (FWHM) value was also observed due to the increase in nitrogen content in the films. The FTIR spectra showed the characteristic peaks at 2958, 2366, 2350, 1610, 1512, 1047 and 710 cm−1 in as grown and nitrogen incorporated ta-C films.
O.s. Panwar - One of the best experts on this subject based on the ideXlab platform.
-
Properties of boron and phosphorous incorporated tetrahedral amorphous carbon films grown using filtered cathodic vacuum Arc Process
Applied Surface Science, 2010Co-Authors: O.s. Panwar, Mohd Alim Khan, Bonthu Satyanarayana, Sushil Kumar, IshpalAbstract:This paper reports the electrical, mechanical, structural and field emission properties of as grown and also boron and phosphorous incorporated tetrahedral amorphous carbon (ta-C) films, deposited using a filtered cathodic vacuum Arc Process. The effect of varying boron and phosphorous content (up to 2.0 at.% in to ta-C) on the conductivity (σD), activation energy (ΔE1), hardness, microstructure, emission threshold (Eturn-ON) and emission current density (J) at 12.5 V/μm of ta-C: B and ta-C: P films deposited at a high negative substrate bias of −300 V are reported. It is observed that both boron and phosphorous incorporation leads to a nearly an order increase in σD and corresponding decrease in ΔE1 and a slight increase in hardness as compared to as grown ta-C films. In the case of field assisted electron emission, it is observed that Eturn-ON increases and J decreases. The changes are attributed to the changes in the sp3/sp2 ratio of the films due to boron and phosphorous incorporation. The effect of boron on ta-C is to give a p-type effect whereas the effect of phosphorous gives n-type doping effect.
-
Characterization of Boron- and Phosphorous-Incorporated Tetrahedral Amorphous Carbon Films Deposited by the Filtered Cathodic Vacuum Arc Process
Japanese Journal of Applied Physics, 2009Co-Authors: O.s. Panwar, Mohd Alim Khan, Bonthu Satyanarayana, Mahesh Kumar, S. M. Shivaprasad, Prakash Narain Dixit, R. BhattacharyyaAbstract:This paper reports the X-ray photoelectron spectroscopy (XPS), X-ray-induced Auger electron spectroscopy (XAES), and Raman studies of boron- and phosphorous-incorporated tetrahedral amorphous carbon (ta-C) films deposited by the filtered cathodic vacuum Arc Process. A systematic study of the influence of varying boron (B) and phosphorous (P) content on the properties of the as-grown ta-C films deposited at high negative substrate bias (-300 V) is reported by analyzing the C 1s, B 1s, and P 1s core levels using photoelectron spectroscopy. The sp3 and sp2 contents in the films were determined by measuring the width of the X-ray-induced Auger peaks. B incorporation in ta-C films up to 2.0 at. % increases the sp2 content and decreases the sp3 content by 3.6%, whereas P incorporation up to 2.0 at. % results in an increase of sp2 content and decrease of sp3 content by ~ 30%. The valence band spectra show changes in the Fermi level as B and P are incorporated into the ta-C films. The characteristic Raman spectra confirm the high sp3 content in the deposited films. Thus, the study demonstrates, in the case of high negative substrate bias films, that a pronounced decrease in sp3 fraction or the diamond-like nature of the ta-C films occurs upon P incorporation in comparison to that upon B incorporation.
-
Reflectance and photoluminescence spectra of as grown and hydrogen and nitrogen incorporated tetrahedral amorphous carbon films deposited using an S bend filtered cathodic vacuum Arc Process
Thin Solid Films, 2006Co-Authors: O.s. Panwar, Mohd Alim Khan, Bonthu Satyanarayana, Prakash Narain Dixit, R. Bhattacharyya, B. Bhattacharjee, Mazhar KhanAbstract:Abstract The study of reflectance and photoluminescence (PL) spectra of as grown and also hydrogen and nitrogen incorporated tetrahedral amorphous carbon (ta-C) films, deposited using an S bend filtered cathodic vacuum Arc Process is reported here. First the effect of negative substrate bias on the properties of as grown ta-C films and next the effect of varying hydrogen and nitrogen partial pressure at a high substrate bias of − 300 V on the properties of hydrogen and nitrogen incorporated ta-C (ta-C:H and ta-C:N) films are reported for the first time. The values of the optical band gap ( E g ) evaluated using the reflectance spectra were found to decrease with the increase of the substrate bias in the as grown ta-C films. Hydrogen incorporation up to 1.9 × 10 − 2 Pa partial pressure in as grown ta-C films increased the values of E g and beyond which the values of E g decreased while the nitrogen incorporation up to 3.0 × 10 − 1 Pa partial pressure has no effect on the E g values. The PL spectra indicated a strong peak at ∼2.66 eV in as grown ta-C films deposited at − 20 V substrate bias. This main peak was found to shift to higher energy with the increase of the substrate bias up to − 200 V and thereafter the PL peak shifted towards the lower energy. Other peak at 3.135 eV starts appearing and this is found to start shifting to higher energy for films deposited at higher substrate bias. The intensity of the main PL peak was enhanced at low temperature and several other peaks started appearing in place of the broad peak at ∼3.16 eV. The peak width and area of both the main peak were found to decrease with the increase of substrate bias in as grown ta-C films and with the increase of the hydrogen and nitrogen partial pressure used in depositing ta-C:H and ta-C:N films. The current models on the source of luminescence in amorphous carbon have been discussed.
-
Characterization of as grown and nitrogen incorporated tetrahedral amorphous carbon films deposited by pulsed unfiltered cathodic vacuum Arc Process
Thin Solid Films, 2005Co-Authors: O.s. Panwar, B.s. Satyanarayana, Mohd Alim Khan, R. BhattacharyyaAbstract:Reported is a study of the as grown and nitrogen incorporated tetrahedral amorphous carbon (ta-C) films deposited by a pulsed unfiltered cathodic vacuum Arc Process using Raman scattering, photoluminescence (PL) and Fourier transform infrared (FTIR) spectroscopy. The influence of the substrate bias in as grown ta-C films and the effect of the nitrogen content in nitrogen incorporated ta-C films under a fixed bias condition were studied. The Raman spectroscopic study showed that, in the present study, the as grown ta-C films deposited at 40 V substrate bias possibly have the highest sp3 bonded carbon concentration, as observed by the large shift in the G peak to ∼1596 cm−1. In the case of the nitrogen incorporated ta-C films, the G peak exhibited a shift towards lower wave number with increasing nitrogen content, suggesting an increase in disorder. The PL spectra indicated a strong peak ∼2.21 eV arising due to extended defects like dislocations followed by a small one ∼1.92 eV which could be identified as a zero phonon line (ZPL) doublet. Another peak at ∼2.63 eV could be attributed to TR12 center. PL peak at ∼2.21 eV showed an inflexion in ta-C films deposited at 40 V substrate bias. An increase in intensity of the PL peak at ∼2.17 eV and its full width at half maximum (FWHM) value was also observed due to the increase in nitrogen content in the films. The FTIR spectra showed the characteristic peaks at 2958, 2366, 2350, 1610, 1512, 1047 and 710 cm−1 in as grown and nitrogen incorporated ta-C films.
-
Space charge limited conduction and electron paramagnetic resonance studies of as grown and nitrogen incorporated tetrahedral amorphous carbon films deposited by pulsed unfiltered cathodic vacuum Arc Process
Diamond and Related Materials, 2004Co-Authors: O.s. Panwar, B.s. Satyanarayana, Mohd Alim Khan, S.k. Gupta, R. BhattacharyyaAbstract:This paper reports the space charge limited conduction (SCLC) and electron paramagnetic resonance (EPR) studies of as grown and nitrogen incorporated tetrahedral amorphous carbon (ta-C) films deposited by pulsed unfiltered cathodic vacuum Arc Process. The effect of varying substrate bias and nitrogen content on the properties of as grown and nitrogen incorporated ta-C films have been studied. The values of density of states (N(EF)) evaluated from SCLC measurements and spin density (Ns) evaluated from EPR studies of as grown ta-C films deposited at 5 V substrate bias are found to be 1.6×1019 cm−3 eV−1 and 6.7×1019 cm−3, respectively, which decrease to 8.7×1018 cm−3 eV−1 and 4.6×1019 cm−3, respectively, with the increase of substrate bias up to 80 V and beyond 80 V substrate bias these values are found to increase. A small amount of nitrogen incorporation up to 3.6 at.% nitrogen content in nitrogen incorporated ta-C films reduces the values of N(EF) and Ns to 1.4×1019 cm−3 eV−1 and 4.3×1019 cm−3, respectively. Beyond 3.6 at.% nitrogen content, the values of N(EF) and Ns are found to increase monotonically to 2.6×1019 cm−3 eV−1 and 1.0×1020 cm−3, respectively, in nitrogen incorporated ta-C films with further increase of nitrogen content up to 15.6 at.%. The local minimum in the values of N(EF) and Ns in as grown ta-C films deposited at 80 V substrate bias arises due to the ability of sp2 sites to pair up. Nitrogen incorporation up to 3.6 at.% in nitrogen incorporated ta-C films seems to compensate the p-type nature and beyond 3.6 at.% nitrogen content the donor electron increases the values of N(EF) and Ns in the films.
R. Bhattacharyya - One of the best experts on this subject based on the ideXlab platform.
-
Characterization of Boron- and Phosphorous-Incorporated Tetrahedral Amorphous Carbon Films Deposited by the Filtered Cathodic Vacuum Arc Process
Japanese Journal of Applied Physics, 2009Co-Authors: O.s. Panwar, Mohd Alim Khan, Bonthu Satyanarayana, Mahesh Kumar, S. M. Shivaprasad, Prakash Narain Dixit, R. BhattacharyyaAbstract:This paper reports the X-ray photoelectron spectroscopy (XPS), X-ray-induced Auger electron spectroscopy (XAES), and Raman studies of boron- and phosphorous-incorporated tetrahedral amorphous carbon (ta-C) films deposited by the filtered cathodic vacuum Arc Process. A systematic study of the influence of varying boron (B) and phosphorous (P) content on the properties of the as-grown ta-C films deposited at high negative substrate bias (-300 V) is reported by analyzing the C 1s, B 1s, and P 1s core levels using photoelectron spectroscopy. The sp3 and sp2 contents in the films were determined by measuring the width of the X-ray-induced Auger peaks. B incorporation in ta-C films up to 2.0 at. % increases the sp2 content and decreases the sp3 content by 3.6%, whereas P incorporation up to 2.0 at. % results in an increase of sp2 content and decrease of sp3 content by ~ 30%. The valence band spectra show changes in the Fermi level as B and P are incorporated into the ta-C films. The characteristic Raman spectra confirm the high sp3 content in the deposited films. Thus, the study demonstrates, in the case of high negative substrate bias films, that a pronounced decrease in sp3 fraction or the diamond-like nature of the ta-C films occurs upon P incorporation in comparison to that upon B incorporation.
-
Reflectance and photoluminescence spectra of as grown and hydrogen and nitrogen incorporated tetrahedral amorphous carbon films deposited using an S bend filtered cathodic vacuum Arc Process
Thin Solid Films, 2006Co-Authors: O.s. Panwar, Mohd Alim Khan, Bonthu Satyanarayana, Prakash Narain Dixit, R. Bhattacharyya, B. Bhattacharjee, Mazhar KhanAbstract:Abstract The study of reflectance and photoluminescence (PL) spectra of as grown and also hydrogen and nitrogen incorporated tetrahedral amorphous carbon (ta-C) films, deposited using an S bend filtered cathodic vacuum Arc Process is reported here. First the effect of negative substrate bias on the properties of as grown ta-C films and next the effect of varying hydrogen and nitrogen partial pressure at a high substrate bias of − 300 V on the properties of hydrogen and nitrogen incorporated ta-C (ta-C:H and ta-C:N) films are reported for the first time. The values of the optical band gap ( E g ) evaluated using the reflectance spectra were found to decrease with the increase of the substrate bias in the as grown ta-C films. Hydrogen incorporation up to 1.9 × 10 − 2 Pa partial pressure in as grown ta-C films increased the values of E g and beyond which the values of E g decreased while the nitrogen incorporation up to 3.0 × 10 − 1 Pa partial pressure has no effect on the E g values. The PL spectra indicated a strong peak at ∼2.66 eV in as grown ta-C films deposited at − 20 V substrate bias. This main peak was found to shift to higher energy with the increase of the substrate bias up to − 200 V and thereafter the PL peak shifted towards the lower energy. Other peak at 3.135 eV starts appearing and this is found to start shifting to higher energy for films deposited at higher substrate bias. The intensity of the main PL peak was enhanced at low temperature and several other peaks started appearing in place of the broad peak at ∼3.16 eV. The peak width and area of both the main peak were found to decrease with the increase of substrate bias in as grown ta-C films and with the increase of the hydrogen and nitrogen partial pressure used in depositing ta-C:H and ta-C:N films. The current models on the source of luminescence in amorphous carbon have been discussed.
-
Characterization of as grown and nitrogen incorporated tetrahedral amorphous carbon films deposited by pulsed unfiltered cathodic vacuum Arc Process
Thin Solid Films, 2005Co-Authors: O.s. Panwar, B.s. Satyanarayana, Mohd Alim Khan, R. BhattacharyyaAbstract:Reported is a study of the as grown and nitrogen incorporated tetrahedral amorphous carbon (ta-C) films deposited by a pulsed unfiltered cathodic vacuum Arc Process using Raman scattering, photoluminescence (PL) and Fourier transform infrared (FTIR) spectroscopy. The influence of the substrate bias in as grown ta-C films and the effect of the nitrogen content in nitrogen incorporated ta-C films under a fixed bias condition were studied. The Raman spectroscopic study showed that, in the present study, the as grown ta-C films deposited at 40 V substrate bias possibly have the highest sp3 bonded carbon concentration, as observed by the large shift in the G peak to ∼1596 cm−1. In the case of the nitrogen incorporated ta-C films, the G peak exhibited a shift towards lower wave number with increasing nitrogen content, suggesting an increase in disorder. The PL spectra indicated a strong peak ∼2.21 eV arising due to extended defects like dislocations followed by a small one ∼1.92 eV which could be identified as a zero phonon line (ZPL) doublet. Another peak at ∼2.63 eV could be attributed to TR12 center. PL peak at ∼2.21 eV showed an inflexion in ta-C films deposited at 40 V substrate bias. An increase in intensity of the PL peak at ∼2.17 eV and its full width at half maximum (FWHM) value was also observed due to the increase in nitrogen content in the films. The FTIR spectra showed the characteristic peaks at 2958, 2366, 2350, 1610, 1512, 1047 and 710 cm−1 in as grown and nitrogen incorporated ta-C films.
-
Space charge limited conduction and electron paramagnetic resonance studies of as grown and nitrogen incorporated tetrahedral amorphous carbon films deposited by pulsed unfiltered cathodic vacuum Arc Process
Diamond and Related Materials, 2004Co-Authors: O.s. Panwar, B.s. Satyanarayana, Mohd Alim Khan, S.k. Gupta, R. BhattacharyyaAbstract:This paper reports the space charge limited conduction (SCLC) and electron paramagnetic resonance (EPR) studies of as grown and nitrogen incorporated tetrahedral amorphous carbon (ta-C) films deposited by pulsed unfiltered cathodic vacuum Arc Process. The effect of varying substrate bias and nitrogen content on the properties of as grown and nitrogen incorporated ta-C films have been studied. The values of density of states (N(EF)) evaluated from SCLC measurements and spin density (Ns) evaluated from EPR studies of as grown ta-C films deposited at 5 V substrate bias are found to be 1.6×1019 cm−3 eV−1 and 6.7×1019 cm−3, respectively, which decrease to 8.7×1018 cm−3 eV−1 and 4.6×1019 cm−3, respectively, with the increase of substrate bias up to 80 V and beyond 80 V substrate bias these values are found to increase. A small amount of nitrogen incorporation up to 3.6 at.% nitrogen content in nitrogen incorporated ta-C films reduces the values of N(EF) and Ns to 1.4×1019 cm−3 eV−1 and 4.3×1019 cm−3, respectively. Beyond 3.6 at.% nitrogen content, the values of N(EF) and Ns are found to increase monotonically to 2.6×1019 cm−3 eV−1 and 1.0×1020 cm−3, respectively, in nitrogen incorporated ta-C films with further increase of nitrogen content up to 15.6 at.%. The local minimum in the values of N(EF) and Ns in as grown ta-C films deposited at 80 V substrate bias arises due to the ability of sp2 sites to pair up. Nitrogen incorporation up to 3.6 at.% in nitrogen incorporated ta-C films seems to compensate the p-type nature and beyond 3.6 at.% nitrogen content the donor electron increases the values of N(EF) and Ns in the films.
-
XPS and XAES studies of as grown and nitrogen incorporated tetrahedral amorphous carbon films deposited by pulsed unfiltered cathodic vacuum Arc Process
Applied Surface Science, 2004Co-Authors: O.s. Panwar, B.s. Satyanarayana, Mohd Alim Khan, S. M. Shivaprasad, Y. Aparna, R. BhattacharyyaAbstract:Abstract This paper reports the X-ray photoelectron spectroscopy (XPS) and X-ray induced Auger electron spectroscopy (XAES) studies of as grown and nitrogen incorporated tetrahedral amorphous carbon (ta-C) films deposited by pulsed unfiltered cathodic vacuum Arc Process. The effect of varying substrate bias and nitrogen content on the properties of the as grown and the nitrogen incorporated ta-C films has been studied. The XPS spectra indicate that in the as grown ta-C films the C 1s peak occurs at 285.15±0.08 eV and the binding energy (BE) marginally decreases with the increase of substrate bias. The nitrogen incorporated ta-C films show N 1s peak at 399.46±0.10 eV in addition to the C 1s peak. The peak position of C 1s remains unchanged with nitrogen incorporation, whereas the N 1s peak seems to marginally decrease in BE, with increasing nitrogen content. From the values of the parameter D, the energy width between the highest maximum and the lowest minimum value of the derivative of C (KLL) spectra, sp2, sp3 and sp3/sp2 ratio were evaluated. The values of D, sp2, sp3 and sp3/sp2 ratio for the as grown ta-C films are found to be 17.16 eV, 35.7%, 64.3% and 1.80, respectively. The values of D and sp2 fraction are found to decrease to 16.19 eV and 23.9% and those of sp3 and sp3/sp2 ratio are found to increase to 76.1% and 3.18 in the case of ta-C films deposited at an applied substrate bias of 40 V. In the case of applied substrate bias beyond 40 V, the values of these parameters show a reversal in the trend. The nitrogen incorporated ta-C films with 3.6 at.% nitrogen content do not show any change in the values of D, sp2, sp3 and sp3/sp2 ratio. With further increase in the nitrogen content up to 15.6 at.%, the values of D and sp2 fraction decrease continuously to 15.87 eV and 20.1% and the values of sp3 and sp3/sp2 ratio increase to 79.9% and 3.98, respectively. The study suggests that, at certain conditions of nitrogen incorporation in the case of ta-C films, there is an increase in sp3 fraction or the diamond like nature of the ta-C films.
P. J. Martin - One of the best experts on this subject based on the ideXlab platform.
-
Alignment and switching behaviors of liquid crystal on a-Si Ox thin films deposited by a filtered cathodic Arc Process
Applied Physics Letters, 2007Co-Authors: P. J. Martin, Yasuhumi Asao, Avi Bendavid, Céline Comte, H Miyata, Y. Ishida, Akira SakaiAbstract:A new method is described for the preparation of silicon oxide layers, which produces vertical alignment of liquid crystal with controlled pretilt angles, by a reactive filtered cathodic Arc deposition under oblique incidence geometry. The pretilt angle is dependent on the angle of deposition, but is not simply caused by the surface roughness. The achievable pretilt angle by this method is ~5.5°, which allows uniform switching behavior under an applied electric field.
-
review of the filtered vacuum Arc Process and materials deposition
Thin Solid Films, 2001Co-Authors: P. J. MartinAbstract:The problem of removing macroparticle contamination from cathodic Arc deposition technology has been addressed by several techniques. These techniques have been sufficiently successful that in recent years improved coatings have been developed and advanced applications are starting to appear. The present paper is a review of these advances and the properties of new materials synthesised using different filtered cathodic Arc configurations.
-
The filtered Arc Process and materials deposition
Surface & Coatings Technology, 2001Co-Authors: P. J. Martin, Avi BendavidAbstract:Abstract Compound materials have been synthesised by reactive filtered Arc deposition using both single and multi-elemental cathodes. Specifically, hard coatings of Al-SiO x and Al-SiN x have been deposited with refractive indices n 550 of 1.65 and 2.20, respectively. The indentation hardness of Al-SiN x coatings was 22 GPa. In addition, Al-SiN x has been mixed with TiN x by a dual filtered Arc method to produce nanocomposite TiAlSiN x films. Hard coatings of NbC and NbN have been synthesised by reactive deposition in methane and nitrogen, respectively, to produce hardness values in excess of 40 GPa. NbN/Ni nanocomposite coatings were deposited with a hardness of 63 GPa.
-
The deposition of TiN thin films by energetic condensation from a filtered cathodic Arc Process
Proceedings of 17th International Symposium on Discharges and Electrical Insulation in Vacuum, 1996Co-Authors: P. J. Martin, Avi Bendavid, T.j. KinderAbstract:A filtered cathodic Arc source has been used to deposit thin films of titanium nitride. The properties of the films are influenced by the nature of the condensation Process. TiN films may be deposited directly onto heated substrates in a nitrogen atmosphere or onto unbiased substrates at ambient temperature by condensing the Ti/sup +/ ion beam under 500 eV N/sub 2//sup +/ nitrogen ion bombardment. In the latter case the film stoichiometry was varied from a N:Ti ratio of 0.8 to 1.2 by controlling the relative arrival rates of Ti and nitrogen ions. Simple models are used to describe the evolution of compressive stress as a function of arrival ratio, and the composition of the ion assisted TiN films.
Mohd Alim Khan - One of the best experts on this subject based on the ideXlab platform.
-
Properties of boron and phosphorous incorporated tetrahedral amorphous carbon films grown using filtered cathodic vacuum Arc Process
Applied Surface Science, 2010Co-Authors: O.s. Panwar, Mohd Alim Khan, Bonthu Satyanarayana, Sushil Kumar, IshpalAbstract:This paper reports the electrical, mechanical, structural and field emission properties of as grown and also boron and phosphorous incorporated tetrahedral amorphous carbon (ta-C) films, deposited using a filtered cathodic vacuum Arc Process. The effect of varying boron and phosphorous content (up to 2.0 at.% in to ta-C) on the conductivity (σD), activation energy (ΔE1), hardness, microstructure, emission threshold (Eturn-ON) and emission current density (J) at 12.5 V/μm of ta-C: B and ta-C: P films deposited at a high negative substrate bias of −300 V are reported. It is observed that both boron and phosphorous incorporation leads to a nearly an order increase in σD and corresponding decrease in ΔE1 and a slight increase in hardness as compared to as grown ta-C films. In the case of field assisted electron emission, it is observed that Eturn-ON increases and J decreases. The changes are attributed to the changes in the sp3/sp2 ratio of the films due to boron and phosphorous incorporation. The effect of boron on ta-C is to give a p-type effect whereas the effect of phosphorous gives n-type doping effect.
-
Characterization of Boron- and Phosphorous-Incorporated Tetrahedral Amorphous Carbon Films Deposited by the Filtered Cathodic Vacuum Arc Process
Japanese Journal of Applied Physics, 2009Co-Authors: O.s. Panwar, Mohd Alim Khan, Bonthu Satyanarayana, Mahesh Kumar, S. M. Shivaprasad, Prakash Narain Dixit, R. BhattacharyyaAbstract:This paper reports the X-ray photoelectron spectroscopy (XPS), X-ray-induced Auger electron spectroscopy (XAES), and Raman studies of boron- and phosphorous-incorporated tetrahedral amorphous carbon (ta-C) films deposited by the filtered cathodic vacuum Arc Process. A systematic study of the influence of varying boron (B) and phosphorous (P) content on the properties of the as-grown ta-C films deposited at high negative substrate bias (-300 V) is reported by analyzing the C 1s, B 1s, and P 1s core levels using photoelectron spectroscopy. The sp3 and sp2 contents in the films were determined by measuring the width of the X-ray-induced Auger peaks. B incorporation in ta-C films up to 2.0 at. % increases the sp2 content and decreases the sp3 content by 3.6%, whereas P incorporation up to 2.0 at. % results in an increase of sp2 content and decrease of sp3 content by ~ 30%. The valence band spectra show changes in the Fermi level as B and P are incorporated into the ta-C films. The characteristic Raman spectra confirm the high sp3 content in the deposited films. Thus, the study demonstrates, in the case of high negative substrate bias films, that a pronounced decrease in sp3 fraction or the diamond-like nature of the ta-C films occurs upon P incorporation in comparison to that upon B incorporation.
-
Effect of hydrogen and nitrogen incorporation on the properties of tetrahedral amorphous carbon films grown using S bend filtered cathodic vacuum Arc Process
Indian Journal of Pure & Applied Physics, 2008Co-Authors: O. S. Panwara, Mohd Alim Khan, Sushil Kumar, G. Bhagavanarayana, Pooja Dixit, C. M. S. RauthanAbstract:The electrical and mechanical properties of as- grown and also hydrogen and nitrogen incorporated tetrahedral amorphous carbon (ta-C) films, deposited using S bend filtered cathodic vacuum Arc Process have been reported. First, the effect of varying negative substrate bias on the dark conductivity (σ D ), activation energy (ΔE 1 ) and residual stress of as grown ta-C films and next the effect of varying hydrogen and nitrogen partial pressure on the properties of ta-C: H and ta-C: N films deposited at a high negative substrate bias of-300V are reported. The value of σ D is minimum at 10 -4 ohm -1 c l in as- grown ta-C films deposited at -150V substrate bias whereas the value of ΔE 1 is maximum at 0.22 eV and residual stress is maximum at 0.71 GPa in as- grown ta-C films deposited at -200 V applied substrate bias and it is found to depend on the substrate bias. Hydrogen incorporation in ta-C films decreases the value of σ D to 1.0×10 -9 ohm -1 cm -1 , increases the values of ΔE 1 to 0.45 eV continuously with the increase of hydrogen partial pressure up to 1.4×10 -3 mbar whereas nitrogen incorporation in ta-C films increases the value of σ D to 10 -1 ohm -1 cm -1 and decreases the value of AE, to 0.07 eV continuously with the increase of nitrogen content up to 16.3 at. %. Low amount of hydrogen incorporation in ta-C films up to 7.4×10 -5 mbar hydrogen partial pressure reduces the value of residual stress and larger amount of hydrogen incorporation beyond this pressure increases the value of residual stress whereas nitrogen incorporation in ta-C films reduces the values of residual stress. The effect of hydrogen on ta-C is to give a modest gain in semi-conducting properties by passivating some defect states whereas the effect of nitrogen gives n-type doping effect in ta-C films.
-
Reflectance and photoluminescence spectra of as grown and hydrogen and nitrogen incorporated tetrahedral amorphous carbon films deposited using an S bend filtered cathodic vacuum Arc Process
Thin Solid Films, 2006Co-Authors: O.s. Panwar, Mohd Alim Khan, Bonthu Satyanarayana, Prakash Narain Dixit, R. Bhattacharyya, B. Bhattacharjee, Mazhar KhanAbstract:Abstract The study of reflectance and photoluminescence (PL) spectra of as grown and also hydrogen and nitrogen incorporated tetrahedral amorphous carbon (ta-C) films, deposited using an S bend filtered cathodic vacuum Arc Process is reported here. First the effect of negative substrate bias on the properties of as grown ta-C films and next the effect of varying hydrogen and nitrogen partial pressure at a high substrate bias of − 300 V on the properties of hydrogen and nitrogen incorporated ta-C (ta-C:H and ta-C:N) films are reported for the first time. The values of the optical band gap ( E g ) evaluated using the reflectance spectra were found to decrease with the increase of the substrate bias in the as grown ta-C films. Hydrogen incorporation up to 1.9 × 10 − 2 Pa partial pressure in as grown ta-C films increased the values of E g and beyond which the values of E g decreased while the nitrogen incorporation up to 3.0 × 10 − 1 Pa partial pressure has no effect on the E g values. The PL spectra indicated a strong peak at ∼2.66 eV in as grown ta-C films deposited at − 20 V substrate bias. This main peak was found to shift to higher energy with the increase of the substrate bias up to − 200 V and thereafter the PL peak shifted towards the lower energy. Other peak at 3.135 eV starts appearing and this is found to start shifting to higher energy for films deposited at higher substrate bias. The intensity of the main PL peak was enhanced at low temperature and several other peaks started appearing in place of the broad peak at ∼3.16 eV. The peak width and area of both the main peak were found to decrease with the increase of substrate bias in as grown ta-C films and with the increase of the hydrogen and nitrogen partial pressure used in depositing ta-C:H and ta-C:N films. The current models on the source of luminescence in amorphous carbon have been discussed.
-
Characterization of as grown and nitrogen incorporated tetrahedral amorphous carbon films deposited by pulsed unfiltered cathodic vacuum Arc Process
Thin Solid Films, 2005Co-Authors: O.s. Panwar, B.s. Satyanarayana, Mohd Alim Khan, R. BhattacharyyaAbstract:Reported is a study of the as grown and nitrogen incorporated tetrahedral amorphous carbon (ta-C) films deposited by a pulsed unfiltered cathodic vacuum Arc Process using Raman scattering, photoluminescence (PL) and Fourier transform infrared (FTIR) spectroscopy. The influence of the substrate bias in as grown ta-C films and the effect of the nitrogen content in nitrogen incorporated ta-C films under a fixed bias condition were studied. The Raman spectroscopic study showed that, in the present study, the as grown ta-C films deposited at 40 V substrate bias possibly have the highest sp3 bonded carbon concentration, as observed by the large shift in the G peak to ∼1596 cm−1. In the case of the nitrogen incorporated ta-C films, the G peak exhibited a shift towards lower wave number with increasing nitrogen content, suggesting an increase in disorder. The PL spectra indicated a strong peak ∼2.21 eV arising due to extended defects like dislocations followed by a small one ∼1.92 eV which could be identified as a zero phonon line (ZPL) doublet. Another peak at ∼2.63 eV could be attributed to TR12 center. PL peak at ∼2.21 eV showed an inflexion in ta-C films deposited at 40 V substrate bias. An increase in intensity of the PL peak at ∼2.17 eV and its full width at half maximum (FWHM) value was also observed due to the increase in nitrogen content in the films. The FTIR spectra showed the characteristic peaks at 2958, 2366, 2350, 1610, 1512, 1047 and 710 cm−1 in as grown and nitrogen incorporated ta-C films.
