A new OPC method for double patterning technology

Abstract

As the VLSI technology scales into deep submicron nodes, Double Patterning Technology (DPT) has shown its necessity for the under 45nm processes. However, the litho-related and process-related issues, such as the overlay control for CD uniformity, decomposition, feature stitching technology and some other problems make up the main challenges for the implementation of DPT. Due to Optical Proximity Correction (OPC), the complexity and data volume of DPT increase dramatically, which severely increase the application cost and create manufacturability problems.In this paper, we mainly talk about the interactions between DPT and OPC and propose a new Model-Based OPC methods for the decomposition in DPT procedures. To address the printing problems with cutting sites for feature split, we introduce an overlap correction method on the stitching locations. For any re-cut and/or redesigned pattern after verification, we categorize DP decompositions and introduce a new Adaptable OPC (Ad-OPC) algorithm by reusing post OPC layout to speed up the correction and improve its convergence according to environment surrounding. The method can be easily incorporated into existing MB-OPC framework. To test this method, total Edge Placement Error (EPE) and runtime are calculated in our experiments. Results show that over 90% runtime can be saved compared with conventional OPC procedure. It increases the robustness and friendliness of pattern correction as well as stitches features back satisfactorily.

Recent research development in physical design for manufacturability

“…3, conflicts exist in this layout with three patterns, 1, 2, and 3. Without using stitches, a popular layout decomposition method, such as the natural split decomposition mentioned in [29], would assign a part of patterns to OPT mask # 1 and the other part of patterns to OPT mask #2, but would result in a conflict between patterns. By inserting a stitch in pattern 1 that assigns respective sub patterns to OPT masks #1 and #2, a better decomposition could be achieved without any conflicts.…”