In semiconductor manufacturing, thousands of process steps are required to produce an integrated circuit (IC) chip; each with a uniformity signature that impacts yield. Typically, non-uniformities can be minimized by tuning process conditions. However, even after extensive process optimization, there’s often a residual signature that needs to be removed. The Z-Height chemistry and hardware set applies a spatial correction aimed at removing these residuals and improving planarity. The pitch doubled self-aligned block (SAB) approach of patterning sub-resolution metal lines is one such integration that benefits from this correction method by improving the block height uniformity to ensure proper pattern transfer and a wider process window. In this paper, we will discuss the approach to correct for the thickness non-uniformities induced by the spin-coating and etch processes of a spin-on glass film. Initial results show a 36% improvement in film thickness variation.
|