The Experts below are selected from a list of 327 Experts worldwide ranked by ideXlab platform
Mark J Kushner - One of the best experts on this subject based on the ideXlab platform.
-
Properties of nonthermal capacitively coupled plasmas generated in narrow quartz tubes for synthesis of silicon na-noparticles
2013 Abstracts IEEE International Conference on Plasma Science (ICOPS), 2013Co-Authors: Sang Heon Song, Romain Le Picard, Uwe R Kortshagen, Steven L. Girshick, Mark J KushnerAbstract:Results from a computational investigation of the fundamental properties of plasma synthesis of silicon nanocrystals (SNCs) using the 2-dimensional hybrid plasma Equipment Model (HPEM) were discussed. The Model reactor comprised quartz tube excited by the two ring electrodes at 25 MHz. Most of SiH4 dissociated in transitioning through the plasma zone. The dissociation products produced mostly Si2H6, SiH3, and SiH2 on the exit.
-
electron energy distributions and anomalous skin depth effects in high plasma density inductively coupled discharges
Physical Review E, 2002Co-Authors: Aleksey V Vasenkov, Mark J KushnerAbstract:: Electron transport in low pressure (<10s mTorr), moderate frequency (<10s MHz) inductively coupled plasmas (ICPs) displays a variety of nonequilibrium characteristics due to their operation in a regime where the mean free paths of electrons are significant fractions of the cell dimensions and the skin depth is anomalous. Proper analysis of transport for these conditions requires a kinetic approach to resolve the dynamics of the electron energy distribution (EED) and its non-Maxwellian character. To facilitate such an investigation, a method was developed for Modeling electron-electron collisions in a Monte Carlo simulation and the method was incorporated into a two-dimensional plasma Equipment Model. Electron temperatures, electron densities, and EEDs obtained using the Model were compared with measurements for ICPs sustained in argon. It was found that EEDs were significantly depleted at low energies in regimes dominated by noncollisional heating, typically within the classical electromagnetic skin depth. Regions of positive and negative power deposition were observed for conditions where the absorption of the electric field was both monotonic and nonmonotonic.
-
Surface kinetics and plasma Equipment Model for Si etching by fluorocarbon plasmas
Journal of Applied Physics, 2000Co-Authors: Da Zhang, Mark J KushnerAbstract:Plasma-surface interactions during plasma etching are important in that, in addition to determining the rate and quality of the etch, they can also influence the properties of the bulk plasma. To address this coupling of bulk and surface processes the surface kinetics Model (SKM) was developed as a module in the two-dimensional hybrid plasma Equipment Model (HPEM) with the goal of combining plasma chemistry and surface chemistry in a self-consistent fashion. The SKM obtains reactive fluxes to the surface from the HPEM, and generates the surface species coverages and the returning fluxes to the plasma by implementing a user defined surface reaction mechanism. Although the SKM is basically a surface-site-balance Model, extensions to those algorithms have been made to include an overlying passivation layer through which reactants and products diffuse. Etching of Si in an inductively coupled plasma sustained in Ar/C2F6 was investigated using the SKM. Results from parametric studies are used to demonstrate the...
-
The effect of radio frequency plasma processing reactor circuitry on plasma characteristics
Journal of Applied Physics, 1998Co-Authors: Shahid Rauf, Mark J KushnerAbstract:Past experiments have demonstrated that details of the external electrical circuitry can strongly influence the performance of radio frequency (rf) plasma processing reactors. Seemingly minor changes in the circuit, such as changing cable lengths, can lead to significantly different plasma characteristics. To investigate these couplings, a plasma Equipment Model has been developed which consists of a linked reactor simulation and a circuit Model. In this hierarchy the results of the reactor simulation are periodically used in the circuit Model to construct a simple representation of the plasma consisting of sheaths and resistors which are connected to the external circuit. Voltages (dc, fundamental and harmonics) and currents at all electrodes and reactor surfaces are computed, and are then employed as boundary conditions for the plasma reactor simulation. The Models were used to investigate the effects of operating conditions, reactor geometry and stray coupling on the electrical characteristics of asymm...
-
Virtual plasma Equipment Model: a tool for investigating feedback control in plasma processing Equipment
IEEE Transactions on Semiconductor Manufacturing, 1998Co-Authors: Shahid Rauf, Mark J KushnerAbstract:As microelectronics device feature sizes continue to shrink and wafers continue to increase in size, it is necessary to have tighter tolerances during the fabrication process to maintain high yields. Feedback control has, therefore, become an important issue in plasma processing Equipment design; comprehensive plasma Equipment Models linked to control algorithms would greatly aid in the investigation and optimal selection of control strategies. This paper reports on a numerical plasma simulation tool, the virtual plasma Equipment Model (VPEM), which addresses this need to test feedback control strategies and algorithms on plasma processing Equipment. The VPEM is an extension of the hybrid plasma Equipment Model which has been augmented by sensors and actuators, linked together through a programmable controller. The sensors emulate experimental measurements of species densities, fluxes, and energies, while the actuators change process parameters such as pressure, inductive power, capacitive power, electrode voltages, and mole fraction of gases. Controllers were designed using a response surface based methodology. Results are presented from studies in which these controllers were used to compensate for a leak of N/sub 2/ into an Ar discharge, to stably control drifts in process parameters such as pressure and power in Ar and Ar/Cl/sub 2/, and to nullify the effects of long term changes in wall conditions in Cl/sub 2/ containing plasmas. A new strategy for improving the ion energy flux uniformity in capacitively coupled discharges using feedback control techniques is also explored.
Liu Jia - One of the best experts on this subject based on the ideXlab platform.
-
Research on the Modeling and Implementation Technology of Virtual Machining Environment
Computer Simulation, 2007Co-Authors: Liu JiaAbstract:The construction of virtual machining environment (VME) is an important aspect for establishing virtual machining system. A hierarchical Model of VME, which is comprised of component layer, Equipment layer and environment layer, was proposed. The component Model compasses geometry Model and physics attribute simulation Model. Both the Equipment Model and the environment Model are comprised of configuration Model and control Model. The implementation technologies and methods of such Models were discussed. An instance of VME was given to validate the proposed technologies.
Shahid Rauf - One of the best experts on this subject based on the ideXlab platform.
-
synchronous pulse plasma operation upon source and bias radio frequencys for inductively coupled plasma for highly reliable gate etching technology
Japanese Journal of Applied Physics, 2009Co-Authors: Ken Tokashiki, Shahid Rauf, Samer Banna, Kyoungsub Shin, Valentin N Todorow, Jeongdong Choe, Kartik Ramaswamy, Ankur Agarwal, Kenneth S Collins, Sangjun ChoiAbstract:Synchronous pulse operation upon both source and bias RFs for inductively coupled plasma (ICP) etching system, having both dynamic matching networks and RF frequency-sweeping to ensure the lowest RF reflected power, is introduced for the first time. A superior performance of synchronous pulse operation to conventional continuous wave (cw) as well as source pulse operations is confirmed through plasma diagnostics by using Langmuir probe, plasma simulation by using hybrid plasma Equipment Model (HPEM) and etching performance. Significant reduction of RF power reflection during pulse operation as well as improvement of 35 nm gate critical dimension (CD) uniformity for sub-50 nm dynamic random access memory (DRAM) are achieved by adapting synchronous pulse plasma etching technology. It is definitely expected that synchronous pulse plasma system would have a great ability from a perspective of robustness on fabrication site, excellent gate CD controllability and minimization of plasma induced damage (PID) related device performance degradation.
-
Model for a multiple step deep si etch process
Journal of Vacuum Science and Technology, 2002Co-Authors: Shahid Rauf, William J Dauksher, Stephen B Clemens, Kenneth H SmithAbstract:A multiple-step deep Si etch process involving separate etching and polymerization steps is often employed for fabrication of microelectromechanical systems, microfluidics devices, and other assorted deep structures in Si. An integrated plasma Equipment-feature evolution Model for this multiple-step deep Si etch process is described in this article. In the two-dimensional plasma Equipment Model, the etching (SF6/O2) and polymerization [octafluorocyclobutane(c-C4F8)] chemistries are separately simulated assuming steady-state conditions. The outputs of the Equipment simulations are combined in a string-based feature profile evolution Model to simulate the multiple-step deep Si etch process. In the plasma Equipment Models, detailed gas phase plasma chemistries including electron impact processes, ion–molecule reactions, and neutral chemistry have been considered for both the etching and polymerization gas mixtures. The plasma–surface interaction mechanisms in the feature profile evolution Model are based on ...
-
The effect of radio frequency plasma processing reactor circuitry on plasma characteristics
Journal of Applied Physics, 1998Co-Authors: Shahid Rauf, Mark J KushnerAbstract:Past experiments have demonstrated that details of the external electrical circuitry can strongly influence the performance of radio frequency (rf) plasma processing reactors. Seemingly minor changes in the circuit, such as changing cable lengths, can lead to significantly different plasma characteristics. To investigate these couplings, a plasma Equipment Model has been developed which consists of a linked reactor simulation and a circuit Model. In this hierarchy the results of the reactor simulation are periodically used in the circuit Model to construct a simple representation of the plasma consisting of sheaths and resistors which are connected to the external circuit. Voltages (dc, fundamental and harmonics) and currents at all electrodes and reactor surfaces are computed, and are then employed as boundary conditions for the plasma reactor simulation. The Models were used to investigate the effects of operating conditions, reactor geometry and stray coupling on the electrical characteristics of asymm...
-
Virtual plasma Equipment Model: a tool for investigating feedback control in plasma processing Equipment
IEEE Transactions on Semiconductor Manufacturing, 1998Co-Authors: Shahid Rauf, Mark J KushnerAbstract:As microelectronics device feature sizes continue to shrink and wafers continue to increase in size, it is necessary to have tighter tolerances during the fabrication process to maintain high yields. Feedback control has, therefore, become an important issue in plasma processing Equipment design; comprehensive plasma Equipment Models linked to control algorithms would greatly aid in the investigation and optimal selection of control strategies. This paper reports on a numerical plasma simulation tool, the virtual plasma Equipment Model (VPEM), which addresses this need to test feedback control strategies and algorithms on plasma processing Equipment. The VPEM is an extension of the hybrid plasma Equipment Model which has been augmented by sensors and actuators, linked together through a programmable controller. The sensors emulate experimental measurements of species densities, fluxes, and energies, while the actuators change process parameters such as pressure, inductive power, capacitive power, electrode voltages, and mole fraction of gases. Controllers were designed using a response surface based methodology. Results are presented from studies in which these controllers were used to compensate for a leak of N/sub 2/ into an Ar discharge, to stably control drifts in process parameters such as pressure and power in Ar and Ar/Cl/sub 2/, and to nullify the effects of long term changes in wall conditions in Cl/sub 2/ containing plasmas. A new strategy for improving the ion energy flux uniformity in capacitively coupled discharges using feedback control techniques is also explored.
Da Zhang - One of the best experts on this subject based on the ideXlab platform.
-
Surface kinetics and plasma Equipment Model for Si etching by fluorocarbon plasmas
Journal of Applied Physics, 2000Co-Authors: Da Zhang, Mark J KushnerAbstract:Plasma-surface interactions during plasma etching are important in that, in addition to determining the rate and quality of the etch, they can also influence the properties of the bulk plasma. To address this coupling of bulk and surface processes the surface kinetics Model (SKM) was developed as a module in the two-dimensional hybrid plasma Equipment Model (HPEM) with the goal of combining plasma chemistry and surface chemistry in a self-consistent fashion. The SKM obtains reactive fluxes to the surface from the HPEM, and generates the surface species coverages and the returning fluxes to the plasma by implementing a user defined surface reaction mechanism. Although the SKM is basically a surface-site-balance Model, extensions to those algorithms have been made to include an overlying passivation layer through which reactants and products diffuse. Etching of Si in an inductively coupled plasma sustained in Ar/C2F6 was investigated using the SKM. Results from parametric studies are used to demonstrate the...
Xin Xu - One of the best experts on this subject based on the ideXlab platform.
-
iec 61850 universal database information Model and design method for interface of iec 61850 universal database information Model
2012Co-Authors: Mingzhi Geng, Hao Ren, Haidong Zhang, Xin XuAbstract:The invention provides an IEC 61850 universal database information Model and a design method for an interface of the IEC 61850 universal database information Model. The database Model consists of an information Model, an Equipment Model and an application Model, wherein the information Model obeys IEC 61850; the Equipment Model obeys IEC 61970; the information Model comprises engineering instantiation configuration information of intelligent electronic Equipment; and the engineering instantiation configuration information comprises a Model type database table, a data type database table, a template type database table and a communication type database table. By a database design with three layers of frameworks, so that a standard Model is multiplexed; a database can be automatically established by directly adopting a security coding device (SCD) Model file, and an incidence relation among the information Model, the Equipment Model and the application Model can be automatically constructed; therefore, the engineering debugging period and the maintenance cost can be obviously reduced; the database information Model based on the universal data type is constructed; a search mode quoted by a data object based on a character string format is designed; moreover, an open access interface is supplied; and the IEC 61850 universal database information Model is suitable for different database platforms.