AVS 47th International Symposium
    Plasma Science and Technology Wednesday Sessions
       Session PS-WeP

Paper PS-WeP26
Simulation of the Production of Atomic Hydrogen in a Low-pressure-arc-discharge-based Source

Wednesday, October 4, 2000, 11:00 am, Room Exhibit Hall C & D

Session: Poster Session
Presenter: D.I. Proskurovsky, Institute of High Current Electronics, Russia
Authors: D.I. Proskurovsky, Institute of High Current Electronics, Russia
V.A. Kagadei, Research Institute of Semiconductor Devices, Russia
A.V. Kozyrev, Institute of High Current Electronics, Russia
I.V. Osipov, Tomsk University of Control Systems and Radioelectronics, Russia
Correspondent: Click to Email
Treatment of semiconductor and metallic materials in atomic hydrogen is a promising method used in microelectronic and nanoelectronic technologies for desired modification of their properties at the surface, at interfaces, and in the bulk. To produce atomic hydrogen, dissociation of hydrogen molecules in the plasma of a gas discharge is often used. A quantitative model has been proposed which describes the gas discharge and the processes responsible for the production of atomic hydrogen in a cylindrical cell of an atomic hydrogen source based on a low-pressure arc discharge. At the first stage of simulation the principal plasma parameters (the electron and ion densities, the currents of ions, fast electrons, and plasma electrons, and the currents of thermionic and secondary gamma-electrons) were calculated after which, based on the criterion for current self-sustaining, a calculation of the current-voltage characteristics (CVC's) of the discharge was performed. At the second stage the rate of production of atomic hydrogen was calculated for different parameters of the discharge. The following mechanisms for the generation of hydrogen atoms were considered: impact dissociation of molecules by fast electrons accelerated in the cathode fall region, dissociation of the discharge column plasma by thermal electrons, and dissociation at the surface of a hot cathode. The spatial distribution of the atomic hydrogen flux onto the end wall of the discharge cell has been calculated. The calculated CVC's describe adequately the experimental relations obtained for wide ranges of discharge currents and hydrogen flow rates. This has made it possible to refine some constants of unit processes, such as the coefficient of secondary ion-electron emission, the average energy going into the formation of an electron-ion pair, and the temperature of the hot cathode. The atomic hydrogen yield was estimated by the intensity of the luminescent emission from a luminophor and with the help of a sensor based on a thin-film resistor. Comparison of experimental and theoretical dependences of the atomic hydrogen yield on the discharge current, the gas flow rate, and the position of the extraction hole suggests that the proposed model describes adequately the process of production of atomic hydrogen.