A two-level prediction model for deep reactive ion etch (DRIE)

The authors contribute a quantitative and systematic model to capture etch non-uniformity in deep reactive ion etch of MEMS devices. Non-uniformity depends on uneven distributions of ion and neutral species at the wafer level, and local consumption at the die level. An ion neutral synergism model is constructed from data obtained from several layouts of differing layout pattern densities, and is used to predict wafer level variation with an r.m.s. error below 3%. This model is combined with the die level model, which the authors have reported previously based on T. Hill et al., (2004), on a MEMS layout. The two level model is shown to enable prediction of both within die and wafer scale etch rate variation for arbitrary wafer loadings.