Charging damage during residual metal overetching

The influence of electron and ion temperatures on charging damage during re sidual metal (latent antenna) overetching in high-density plasmas is invest igated by Monte Carlo simulations. The tunneling current through a thin gat e oxide, electrically connected to the antenna, increases significantly wit h electron temperature, mainly as a result of changes in plasma current and ion energy distribution. However, the current decreases with ion temperatu re as ion shading: (a) directly decreases the ion flux to the antenna and ( b) neutralizes the negative charge at the upper mask sidewalls, thus allowi ng more electrons to enter the pattern. The role of exposed antenna areas ( trench bottoms and perimeter) is examined from the perspective of current i mbalance. (C) 1999 American Institute of Physics. [S0003-6951(99)02407-9].