The Experts below are selected from a list of 338514 Experts worldwide ranked by ideXlab platform
S Tripathy - One of the best experts on this subject based on the ideXlab platform.
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influence of stress on structural properties of algan gan high electron mobility transistor layers grown on 150 Mm Diameter si 111 substrate
Journal of Applied Physics, 2013Co-Authors: H F Liu, S B Dolmanan, M Heuken, S J Chua, Lei Zhang, Dongzhi Chi, S TripathyAbstract:Effects of stress imposed by individual nitride layers on structural properties of an AlGaN/GaN high-electron-mobility-transistor (HEMT) structure, which was grown on a 150 Mm Diameter Si (111) substrate by metal-organic chemical vapor deposition employing high-temperature step-graded AlxGa1−xN/AlN buffer layers, were studied using transmission electron microscopy, visible micro-Raman spectroscopy, and high-resolution x-ray diffraction. It is revealed that all the nitride layers are more or less tensile strained on the Si (111) substrate; however, strain relaxations occurred at all the heterointerfaces except for the AlGaN/(AlN/)GaN two-dimensional electron gas interface, which is desired for achieving high performance HEMT. The wafer curvature, an important parameter for large area epitaxy of GaN-on-Si, is modeled on the basis of stress distribution within individual layers of the multilayered AlGaN/GaN HEMT structure via the close-form expression developed by Olsen and Ettenberg [J. Appl. Phys. 48, 2543...
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algan gan two dimensional electron gas heterostructures on 200 Mm Diameter si 111
Applied Physics Letters, 2012Co-Authors: S Tripathy, Vivian Kaixin Lin, S B Dolmanan, Joyce Pei Ying Tan, R S Kajen, L K Bera, Siew Lang Teo, Krishna M Kumar, S Arulkumaran, S VickneshAbstract:This Letter reports on the epitaxial growth, characterization, and device characteristics of crack-free AlGaN/GaN heterostructures on a 200 Mm Diameter Si(111) substrate. The total nitride stack thickness of the sample grown by the metal-organic chemical vapor deposition technique is about 3.3 ± 0.1 μm. The structural and optical properties of these layers are studied by cross-sectional scanning transmission electron microscopy, high-resolution x-ray diffraction, photoluminescence, and micro-Raman spectroscopy techniques. The top AlGaN/GaN heterointerfaces reveal the formation of a two-dimensional electron gas with average Hall mobility values in the range of 1800 to 1900 cm2/Vs across such 200 Mm Diameter GaN on Si(111) samples. The fabricated 1.5 μm-gate AlGaN/GaN high-electron-mobility transistors exhibited the drain current density of 660 mA/Mm and extrinsic transconductance of 210 mS/Mm. These experimental results show iMmense potential of 200-Mm Diameter GaN-on-silicon technology for electronic devi...
Patricia A Fleming - One of the best experts on this subject based on the ideXlab platform.
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wear of enhanced ultra high molecular weight polyethylene hylamer in combination with a 22 225 Mm Diameter zirconia femoral head
Journal of Bone and Joint Surgery-british Volume, 2003Co-Authors: B M Wroblewski, Paul D Siney, Patricia A FlemingAbstract:We have prospectively studied the wear of enhanced ultra-high molecular-weight polyethylene (Hylamer) in combination with a zirconia femoral head of 22.225 Mm Diameter on a cemented, triple-tapered, collarless, polished stem, the C Stem. The 71 patients who underwent total hip arthroplasty had a mean follow-up of six years (3 to 8). No patient died or was lost to follow-up. The clinical results were excellent with 96% of patients satisfied. There were no revisions. Two cups were considered to be loose radiologically. One was avulsed from the cement in a skiing accident, with a periprosthetic fracture of the femur, but has remained stable for more than seven years. One femur shows radiological appearances which are compatible with a healing infection. One femoral component is at risk of loosening. The mean rate of penetration of the cup was 0.22 Mm/year (0.06 to 0.55). Our results appear to be within the guidelines set by the National Institute of Clinical Excellence. We have discontinued the use of Hylamer despite excellent clinical results and no revisions to date because the high initial rates of penetration did not settle to the expected low levels within the anticipated time.
B M Wroblewski - One of the best experts on this subject based on the ideXlab platform.
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wear of enhanced ultra high molecular weight polyethylene hylamer in combination with a 22 225 Mm Diameter zirconia femoral head
Journal of Bone and Joint Surgery-british Volume, 2003Co-Authors: B M Wroblewski, Paul D Siney, Patricia A FlemingAbstract:We have prospectively studied the wear of enhanced ultra-high molecular-weight polyethylene (Hylamer) in combination with a zirconia femoral head of 22.225 Mm Diameter on a cemented, triple-tapered, collarless, polished stem, the C Stem. The 71 patients who underwent total hip arthroplasty had a mean follow-up of six years (3 to 8). No patient died or was lost to follow-up. The clinical results were excellent with 96% of patients satisfied. There were no revisions. Two cups were considered to be loose radiologically. One was avulsed from the cement in a skiing accident, with a periprosthetic fracture of the femur, but has remained stable for more than seven years. One femur shows radiological appearances which are compatible with a healing infection. One femoral component is at risk of loosening. The mean rate of penetration of the cup was 0.22 Mm/year (0.06 to 0.55). Our results appear to be within the guidelines set by the National Institute of Clinical Excellence. We have discontinued the use of Hylamer despite excellent clinical results and no revisions to date because the high initial rates of penetration did not settle to the expected low levels within the anticipated time.
S Vicknesh - One of the best experts on this subject based on the ideXlab platform.
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algan gan two dimensional electron gas heterostructures on 200 Mm Diameter si 111
Applied Physics Letters, 2012Co-Authors: S Tripathy, Vivian Kaixin Lin, S B Dolmanan, Joyce Pei Ying Tan, R S Kajen, L K Bera, Siew Lang Teo, Krishna M Kumar, S Arulkumaran, S VickneshAbstract:This Letter reports on the epitaxial growth, characterization, and device characteristics of crack-free AlGaN/GaN heterostructures on a 200 Mm Diameter Si(111) substrate. The total nitride stack thickness of the sample grown by the metal-organic chemical vapor deposition technique is about 3.3 ± 0.1 μm. The structural and optical properties of these layers are studied by cross-sectional scanning transmission electron microscopy, high-resolution x-ray diffraction, photoluminescence, and micro-Raman spectroscopy techniques. The top AlGaN/GaN heterointerfaces reveal the formation of a two-dimensional electron gas with average Hall mobility values in the range of 1800 to 1900 cm2/Vs across such 200 Mm Diameter GaN on Si(111) samples. The fabricated 1.5 μm-gate AlGaN/GaN high-electron-mobility transistors exhibited the drain current density of 660 mA/Mm and extrinsic transconductance of 210 mS/Mm. These experimental results show iMmense potential of 200-Mm Diameter GaN-on-silicon technology for electronic devi...
S B Dolmanan - One of the best experts on this subject based on the ideXlab platform.
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influence of stress on structural properties of algan gan high electron mobility transistor layers grown on 150 Mm Diameter si 111 substrate
Journal of Applied Physics, 2013Co-Authors: H F Liu, S B Dolmanan, M Heuken, S J Chua, Lei Zhang, Dongzhi Chi, S TripathyAbstract:Effects of stress imposed by individual nitride layers on structural properties of an AlGaN/GaN high-electron-mobility-transistor (HEMT) structure, which was grown on a 150 Mm Diameter Si (111) substrate by metal-organic chemical vapor deposition employing high-temperature step-graded AlxGa1−xN/AlN buffer layers, were studied using transmission electron microscopy, visible micro-Raman spectroscopy, and high-resolution x-ray diffraction. It is revealed that all the nitride layers are more or less tensile strained on the Si (111) substrate; however, strain relaxations occurred at all the heterointerfaces except for the AlGaN/(AlN/)GaN two-dimensional electron gas interface, which is desired for achieving high performance HEMT. The wafer curvature, an important parameter for large area epitaxy of GaN-on-Si, is modeled on the basis of stress distribution within individual layers of the multilayered AlGaN/GaN HEMT structure via the close-form expression developed by Olsen and Ettenberg [J. Appl. Phys. 48, 2543...
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algan gan two dimensional electron gas heterostructures on 200 Mm Diameter si 111
Applied Physics Letters, 2012Co-Authors: S Tripathy, Vivian Kaixin Lin, S B Dolmanan, Joyce Pei Ying Tan, R S Kajen, L K Bera, Siew Lang Teo, Krishna M Kumar, S Arulkumaran, S VickneshAbstract:This Letter reports on the epitaxial growth, characterization, and device characteristics of crack-free AlGaN/GaN heterostructures on a 200 Mm Diameter Si(111) substrate. The total nitride stack thickness of the sample grown by the metal-organic chemical vapor deposition technique is about 3.3 ± 0.1 μm. The structural and optical properties of these layers are studied by cross-sectional scanning transmission electron microscopy, high-resolution x-ray diffraction, photoluminescence, and micro-Raman spectroscopy techniques. The top AlGaN/GaN heterointerfaces reveal the formation of a two-dimensional electron gas with average Hall mobility values in the range of 1800 to 1900 cm2/Vs across such 200 Mm Diameter GaN on Si(111) samples. The fabricated 1.5 μm-gate AlGaN/GaN high-electron-mobility transistors exhibited the drain current density of 660 mA/Mm and extrinsic transconductance of 210 mS/Mm. These experimental results show iMmense potential of 200-Mm Diameter GaN-on-silicon technology for electronic devi...
