The Experts below are selected from a list of 42372 Experts worldwide ranked by ideXlab platform

Rajab Al-sayegh - One of the best experts on this subject based on the ideXlab platform.

  • Suppressing scratch-induced brittle fracture in silicon by geometric design modification of the abrasive grits
    Elsevier, 2019
    Co-Authors: Andrii M. Kovalchenko, Saurav Goel, Islam M. Zakiev, Evgeniy A. Pashchenko, Rajab Al-sayegh
    Abstract:

    The overarching goal of this research was to investigate the application of spherically shaped abrasive particles in achieving ductile-mode cutting. Scratching experiments were carried out to assess the differences between arbitrarily and spherically shaped diamond and tungsten carbide (WC) grits in inducing brittle fracture or ductile plasticity in single-crystal silicon. It was observed that the arbitrarily shaped particles produce brittle fracture in contrast to the spherically shaped grits. The sharp edges and corners of grits result in High Tensile Stress-concentrated regions causing cracking and spalling. Contrary to this, spherically shaped WC particles induce uniform cutting pressure, which suppresses the extent of the brittle fracture and the mode of material removal was completely dominated by ductile-cutting until a threshold load for ductile-to-brittle transition (the first cracks appearance). These observations are expected to provide a suitable pathway in making the Diamond Wire Sawing machining operations more robust by providing a control on brittle damage. Keywords: Silicon, Diamond, Tungsten carbide, Ductile mode cutting, Scratching, Diamond Wire Sawing machining operation

  • Suppressing scratch-induced brittle fracture in silicon by geometric design modification of the abrasive grits
    Journal of Materials Research and Technology, 2019
    Co-Authors: Andrii M. Kovalchenko, Saurav Goel, Islam M. Zakiev, Evgeniy A. Pashchenko, Rajab Al-sayegh
    Abstract:

    Abstract The overarching goal of this research was to investigate the application of spherically shaped abrasive particles in achieving ductile-mode cutting. Scratching experiments were carried out to assess the differences between arbitrarily and spherically shaped diamond and tungsten carbide (WC) grits in inducing brittle fracture or ductile plasticity in single-crystal silicon. It was observed that the arbitrarily shaped particles produce brittle fracture in contrast to the spherically shaped grits. The sharp edges and corners of grits result in High Tensile Stress-concentrated regions causing cracking and spalling. Contrary to this, spherically shaped WC particles induce uniform cutting pressure, which suppresses the extent of the brittle fracture and the mode of material removal was completely dominated by ductile-cutting until a threshold load for ductile-to-brittle transition (the first cracks appearance). These observations are expected to provide a suitable pathway in making the Diamond Wire Sawing machining operations more robust by providing a control on brittle damage.

Wenkuan Yeh - One of the best experts on this subject based on the ideXlab platform.

  • significantly improving sub 90 nm cmosfet performances with notch gate enhanced High Tensile Stress contact etch stop layer
    Microelectronics Reliability, 2008
    Co-Authors: Chiawei Hsu, Yeankuen Fang, Wenkuan Yeh, Chienting Lin
    Abstract:

    This paper reports to improve performances of sub-90 nm CMOSFETs with a notch-gate structure enhanced High Tensile-Stress contact etch stop layer (CESL). Compared to the conventional vertical-gate CMOSFET with an additional offset spacer, the developed structure has the notch-gate as self-aligned offset spacer and lower parasitic capacitance. Beside, the notch-gate shrinks the distance of the CESL to the channel, thus enhances the channel carrier mobility more efficiently. Consequently, an n-MOSFET with this notch-gate structure showed an extra 7% ION enhancement. For p-MOSFETs, even a Tensile-Stress is not preferable, however, with the structure, an extra 3% ION enhancement was still achieved due to the better channel profile by halo implantation through notch-gate structure.

  • the impacts of High Tensile Stress cesl and geometry design on device performance and reliability for 90 nm soi nmosfets
    Microelectronics Reliability, 2007
    Co-Authors: Chiehming Lai, Yeankuen Fang, Chienting Lin, C W Hsu, Wenkuan Yeh
    Abstract:

    Abstract The thickness effects of High-Tensile-Stress contact etch stop layer (HS CESL) and impact of layout geometry (length of diffusion and gate width) on mobility enhancement of 〈100〉/(100) 90 nm SOI nMOSFETs were studied in detail. Additionally, we also inspected the low frequency characteristic with low-frequency noise investigation for FB-SOI nMOSFETs. Experimental results show that devices with 1100 A HS CESL possess worse characteristics and hot-carrier-induced degradations than devices with 700 A HS CESL due to serious Stress-induced defects happen. The lower plateau of Lorentzian noise spectrum observed from input-referred voltage noise ( S vg ) implies Higher leakage current for the devices with 1100 A HS CESL. On the other hand, we found that devices with narrow gate widths possess Higher driving capacity because of larger fringing electric fields and Higher compressive Stress in direction perpendicular to the channel. Owing to the more serious impact of compressive Stress in direction parallel to the channel, the device performance was degraded particularly for devices with shorter LOD.

  • the geometry effect of contact etch stop layer impact on device performance and reliability for 90 nm soi nmosfets
    IEEE Transactions on Electron Devices, 2006
    Co-Authors: Chiehming Lai, Yeankuen Fang, Chienting Lin, Wenkuan Yeh
    Abstract:

    The thickness effects of a High-Tensile-Stress contact etch stop layer (HS CESL) and the impact of layout geometry (length of diffusion (LOD) and gate width) on the mobility enhancement of lang100rang/(100) 90-nm silicon-on-insulator (SOI) n-channel MOSFETs (nMOSFETs) were studied in detail. Additionally, the low-frequency characteristics were inspected using low-frequency noise investigation for floating body (FB)-SOI nMOSFETs. Experimental results show that a device with a 1100-Aring HS CESL has worse characteristics and hot-carrier-induced degradations than a device with a 700-Aring; HS CESL due to larger Stress-induced defects. The lower plateau of the Lorentzian noise spectrum that was observed from the input-referred voltage noise Svg implies a Higher leakage current for devices with a 1100-Aring HS CESL. On the other hand, it was found that devices with narrow gate widths have Higher driving capacity for a larger fringing electric field and Higher compressive Stress in the direction perpendicular to the channel. Because of the more serious impact of compressive Stress in a direction parallel to the channel, a device with shorter LOD experiences more serious performance degradation

Atsushi Sugeta - One of the best experts on this subject based on the ideXlab platform.

  • High temperature bending fatigue properties of oxide dispersion strengthened platinum rhodium alloy under High axial Stress
    International Journal of Fatigue, 2020
    Co-Authors: A Niwa, Y Akita, Kandai Enomoto, Rintaro Aoyama, Hiroyuki Akebono, Atsushi Sugeta
    Abstract:

    Abstract In this study, High-temperature bending fatigue tests were carried out using an oxide dispersion-strengthened platinum-rhodium alloy at 1400 °C with a relatively High axial Stress. At a low Stress amplitude, creep damage progressed throughout the cross-section of the sample due to axial Stress. However, at a High Stress amplitude, creep damage progressed only in the central part of the direction of thickness and fracturing originated from inside the sample. Elastic-plastic creep analysis also indicated that High Tensile Stress remained inside the sample due to the yielding near the surface. The fact that the life is determined by the creep due to the Stress generated inside of the material is useful for life prediction.

Andrii M. Kovalchenko - One of the best experts on this subject based on the ideXlab platform.

  • Suppressing scratch-induced brittle fracture in silicon by geometric design modification of the abrasive grits
    Elsevier, 2019
    Co-Authors: Andrii M. Kovalchenko, Saurav Goel, Islam M. Zakiev, Evgeniy A. Pashchenko, Rajab Al-sayegh
    Abstract:

    The overarching goal of this research was to investigate the application of spherically shaped abrasive particles in achieving ductile-mode cutting. Scratching experiments were carried out to assess the differences between arbitrarily and spherically shaped diamond and tungsten carbide (WC) grits in inducing brittle fracture or ductile plasticity in single-crystal silicon. It was observed that the arbitrarily shaped particles produce brittle fracture in contrast to the spherically shaped grits. The sharp edges and corners of grits result in High Tensile Stress-concentrated regions causing cracking and spalling. Contrary to this, spherically shaped WC particles induce uniform cutting pressure, which suppresses the extent of the brittle fracture and the mode of material removal was completely dominated by ductile-cutting until a threshold load for ductile-to-brittle transition (the first cracks appearance). These observations are expected to provide a suitable pathway in making the Diamond Wire Sawing machining operations more robust by providing a control on brittle damage. Keywords: Silicon, Diamond, Tungsten carbide, Ductile mode cutting, Scratching, Diamond Wire Sawing machining operation

  • Suppressing scratch-induced brittle fracture in silicon by geometric design modification of the abrasive grits
    Journal of Materials Research and Technology, 2019
    Co-Authors: Andrii M. Kovalchenko, Saurav Goel, Islam M. Zakiev, Evgeniy A. Pashchenko, Rajab Al-sayegh
    Abstract:

    Abstract The overarching goal of this research was to investigate the application of spherically shaped abrasive particles in achieving ductile-mode cutting. Scratching experiments were carried out to assess the differences between arbitrarily and spherically shaped diamond and tungsten carbide (WC) grits in inducing brittle fracture or ductile plasticity in single-crystal silicon. It was observed that the arbitrarily shaped particles produce brittle fracture in contrast to the spherically shaped grits. The sharp edges and corners of grits result in High Tensile Stress-concentrated regions causing cracking and spalling. Contrary to this, spherically shaped WC particles induce uniform cutting pressure, which suppresses the extent of the brittle fracture and the mode of material removal was completely dominated by ductile-cutting until a threshold load for ductile-to-brittle transition (the first cracks appearance). These observations are expected to provide a suitable pathway in making the Diamond Wire Sawing machining operations more robust by providing a control on brittle damage.

Jie Chen - One of the best experts on this subject based on the ideXlab platform.

  • Corrosion of High-Strength Steel Wires under Tensile Stress.
    Materials, 2020
    Co-Authors: Jie Chen
    Abstract:

    The Stress corrosion cracking is the central issue for High-strength wires under High Tensile Stress used in civil engineering. This paper explores the resistance of Stress corrosion cracking of three typical steel wires of High-strength carbon through a laboratory test, combining the actions of Tensile Stress and corrosive solution. Besides, the impact of Tensile Stress and immersion time are also investigated. During the tests, the wires were subject to electrochemical measurements of potentiodynamic polarization and electrochemical impedance spectroscopy, and the microstructure analysis was performed on the fractured cross sections. The obtained results show the following: the High-strength wire, conforming to GB/T 5224, has Higher resistance to the combined actions of Tensile Stress and corrosive solution; Tensile Stress of 70% fracture strength and longer loading-immersion time make the film of corrosion products on steel surface unstable and weaken the corrosion resistance; the surface film consisted of the iron oxide film and the corrosion products film whose components are mainly iron thiocyanate and iron sulphide.