Prediction of Plasma Charging Induced Gate Oxide Tunneling Current and Antenna Dependence by Plasma Charging Probe

Abstract

Introduction Charging damage to thin oxides is an ongoing concern for many plasma steps. While it is known that plasma nonuniformity is the major cause for charging and that damage is the result of excess oxide current from this charging, many aspects of this mechanism are still uncertain. In this work, the Stanford plasma on-wafer real time (SPORT) charging probe was used to better understand how charging damage occurs. In particular, the probe was used to monitor charging voltage evolution during a resist removal step, to demonstrate how current collection increases with antenna area, and to predict damage from charge fluence calculated from probe current data and oxide characteristics.