Ion and neutral energy distributions to the MgO surface and sputtering rates in plasma display panel cells

One of the factors limiting the lifetime of plasma display panels (PDPs) is sputtering of the MgO layer deposited on the dielectric covering the electrode. The goal of the work reported here is to evaluate the influence of different operating conditions on the sputtering rate of the MgO layer in PDPs operating with Xe/Ne mixtures. Sputtering is caused by the ions and fast neutral atoms impacting the surface. Starting with results from a fluid model, we use a Monte Carlo simulation to calculate energy distributions of the ion and fast neutrals arriving on the MgO coated surface for a set of baseline conditions. Estimates of the sputtering yield of MgO are then combined with the energy distributions to evaluate the sputtering rates for matrix and coplanar geometries. Parametric calculations in a simple geometry were performed to examine the effect of gas mixture, gas pressure, cell capacitance, and applied voltage on the sputtering rate of the MgO layer. Our main result is the prediction of longer lifetime for mixtures containing about 20%Xe for both matrix and coplanar geometries.