PLANARIZATION OF ULSI TOPOGRAPHY OVER VARIABLE PATTERN DENSITIES

Resist etch-back SiO2 planarization involving a pattern density compensation mask is described for line-space patterns of various dimensions extending to half-micron feature sizes. An empirical model is used to describe the positional dependence of planarization film thickness upon feature density within an array pattern. Design considerations related to the usage of the planarization "block mask" are discussed, a suitable etch condition is specified, and the planarization etchback method is used to achieve long-range, or global planarization.