Measurement of work-function and ion-induced secondary electron emission coefficient of MgO protective layer in AC PDP

Abstract

Summary form only given. The characteristics of MgO film are very important for the development of recent AC-type plasma display panel(AC-PDP). An ion-induced secondary electron emission coefficient y is one of the MgO film characteristics which correlated to the ignition voltage of PDPs. MgO protective layers from sintered MgO and normal MgO are used for measurement of their work-function and secondary electron emission coefficients y in y-FIB system. Their sizes are 110mm/spl times/60mm and 5000A in thickness. The MgO protective layers are deposited on the dielectric layer by electron beam evaporation method. In this experiment, He, Ne, Ar, N/sub 2/, and Xe ions are used for the measurement of the y and the workfunction. From Auger neutralization mechanism, maximum kinetic energy E/sub k//sup max/ of the ejected secondary electron from MgO single crystal is given by E/sub k//sup max/ = E/sub i/-2/spl phi//sub /spl omega//, where E/sub i/ is the ionization energy and /spl phi//sub /spl omega// is the work-function for the MgO. The work-function can be obtained by /spl phi//sub /spl omega//=(E/sub i/-E/sub k//sup max/)/2, which is based on the Auger neutralization mechanism. For the zero emission of secondary electrons, i.e. /spl gamma/=0 from MgO surface, the maximum kinetic energy E/sub k//sup max/ of secondary electrons is E/sub k//sup max/=0. Hence the work-function /spl phi//sub /spl omega// with /spl gamma/=0 and E/sub k//sup max/=0 is given by /spl phi//sub /spl omega// =E/sub i//2, and where E/sub i/ is the ionization energy, which can be obtained by extrapolation of y versus the ionization energy for various gases, where /spl gamma/=0 from MgO. He, Ne, Ar, N/sub 2/, and Xe ions for different ionization energy are used for measurement of secondary electron emission coefficients along with the work function in /spl gamma/-FIB system. The MgO protective layer from sintered MgO has been found to have higher /spl gamma/ values from 0.0733 up to 0. 1168 than that from normal MgO ranged from 0.0258 to 0.1009 under Ne/sup +/ ion energies from 90eV to 200eV throughout this experiment. The work functions for the MgO protective layer deposited from sintered MgO and normal MgO have been found to be 5.32eV and 5.47eV, respectively, at the acceleration voltage of 90V. These results indicate that the work function of MgO protective layers is dependent on the secondary electron emission coefficient /spl gamma/. Based on these facts, it can be concluded that MgO protective layer deposited from sintered MgO plays an important role in lowering the firing voltages in AC-PDP compared with MgO protective layer from normal MgO.