Effect Of Substrate Potential Research Articles

Effect of Substrate Potential on Plasma Parameters of Magnetic Multicusp Plasma Source

The effect of substrate potential on plasmas produced in a magnetic multicusp plasma source has been studied experimentally. Plasma parameters such as electron temperature and plasma potential are estimated from electron energy distribution function numerically calculated from probe current-voltage characteristics. For a substrate potential of -150 V with respect to the source chamber, which is much lower than substrate floating potentials, the plasma parameters are not affected by the application of the potential. However, for the case where the substrate is shorted with the source chamber, the high energy component of electrons significantly decreases in comparison with the floating case leading to the reduction of electron temperature. In this case, plasma potential is positive with respect to the substrate to suppress electron loss but its absolute value is only of the order of electron temperature in eV, which is much lower than the potential between the plasma and the substrate in the floating case. This discharge mode could be advantageous in significantly reducing the ion impact energy to the substrate plate.

Effects of substrate potential on structure and dynamics of stage-3 graphite intercalated caesium

Effects of substrate potential on structure and dynamics of stage-3 graphite intercalated caesium

Effects of substrate potential on structure and dynamics of stage-3 graphite intercalated caesium

We report a molecular dynamics simulation of stage-3 caesium intercalated graphite, C36Cs, performed with three different barrier heights of the substrate modulation potential to investigate its effect on the two dimensional ‘liquid’ alkali metal layer. The graphite-caesium interactions are modelled via the Lennard-Jones potential with barrier heights: 0·0 eV, 0·0125 eV and 0·0374 eV. The results obtained with the barrier height of 0·0374 eV correspond to a solid state rather than to a liquid and suggest that the barrier heights predicted in references [6] and [7] are overestimated. The influence of the electrostatic interactions on the structure and dynamics of the caesium layer is briefly discussed.

Thermodynamics of two-dimensional helium films on textured substrates

Effects of substrate potential and geometry on the thermodynamics of physisorbed, lowdensity, submonolayer helium films are investigated using a tight-binding formalism, a quantum virial expansion, and a lattice version of potential scattering theory. Calculations for a two-parameter triangular-lattice model are presented which exhibit systematic trends in the specific heat that are in qualitative agreement with presently available experimental data.

Effect of Substrate Potential on Al2O3 Films Prepared by Electron Beam Evaporation

In previous experiments the authors explored the deposition of Al2O3 films on silicon by electron-beam evaporation. These films exhibited unstable offset voltages, measured by C–V techniques, and poor radiation resistance. This paper describes the continuation of this study, with the discovery that electrostatic charges developed on the substrates during the electron-beam deposition process play a significant role in affecting the electrical and physical film properties. These investigations indicate that the buildup of negative charge from stray electrons on insulating substrates apparently repels oxygen ions thus altering the stoichiometry of the final film. Control of this charge buildup alters both the electrical and optical properties of the Al2O3 films. Al2O3 films varying in shades of brown to completely clear are produced by altering the electrostatic fields from −22 V (for the darkest films) measured between substrate and ground to less than −2 V between substrate and ground (for the clearest films). Ultraviolet spectra, radiation results, and C–V data indicate that a significant amount of dissociation takes place from the evaporant source during the electron-beam deposition.