AVS 45th International Symposium
    Plasma Science and Technology Division Monday Sessions
       Session PS-MoM

Paper PS-MoM9
Charging Effects in Profile Evolution during Etching of Silicon in High-Density Plasmas

Monday, November 2, 1998, 11:00 am, Room 318/319/320

Session: Feature Evolution
Presenter: G.S. Hwang, California Institute of Technology
Authors: G.S. Hwang, California Institute of Technology
K.P. Giapis, California Institute of Technology
Correspondent: Click to Email
Charging effects are particularly important when high-density plasmas interact with patterned semiconductor surfaces containing mixed conducting and insulating layers. We employ the Direct Simulation Monte Carlo method to investigate the influence of mask charging by the electron shading effect on profile evolution of polysilicon during etching in a Cl@sub 2@ plasma. We compare simulation results with and without charging as a function of ion temperature and mask thickness. We find that microtrenching and sidewall bowing are significantly affected by mask charging as a result of ion trajectory deflection by the local electric field between the mask sidewalls. The magnitude of the effect depends strongly on mask aspect ratio and shape. Differences in profile evolution during etching of nested and isolated lines could also be attributed to charging. The results reaffirm that feature-scale modeling can no longer exclude mask charging effects.