Distributed and adaptive fracturing for sub-90-nm MDP

In the UDSM regime of 65 nm and below, a majority of mask layers require Resolution Enhancement Techniques (RET) to enhance their printability on the wafer. The RET has a huge amount of impact on the layout data both in terms of size and the polygonal data characteristics. The Optical Proximity Correction (OPC) step would reduce the original layout hierarchy by a large extent. Moreover, OPC would either add a large number of geometries to the layout data or would split the original edges in the layout geometries into segments. As a result, the size of the layout data file would increase manifold which could be several hundreds of gigabytes for a single mask layer. The growth in layout data size along with more complex polygons introduced during OPC necessitates that the fracturing tool produce higher quality fracturing with less turn-around-time (TAT) during Mask Data Preparation (MDP) as well as actual mask-write by the EB machine. The VSB (Variable Shaped Beam) machine differs from traditional raster based e-beam machines in many ways. The VSB machine writing time as well as the quality of the masks written by it is significantly affected by the quality of fracturing compared to a raster based mask writer. The two requirements, namely, of reducing the TAT for MDP and increasing the quality of the mask written by mask writer usually counteract with each other. In this paper, we propose a scheme that addresses both the issues.