Localization concept of re-decomposition area to fix hotspots for LELE process

ABSTRACT Among several double patterning methods, Litho-Etch-Litho-Etch type DPT is known to have an advantage of layout flexibility. There are two problems when a hotspot, which is not fixable by tuning OPC, is detected on a wafer or during lithography compliance verification. One is to redo decompos ition, OPC and verification is quite time consuming. The other is a risk to introduce a new hotspot at different locations. In this report, a new method to fix hotspot with layout modification of limited area will be presented. The proposed method can reduce not only repair turnaround time but also a risk of new hotspot generation. Keywords: Double patterning, DFM, LELE, layout modification, hotspot, decomposition 1. INTRODUCTION It has been a long time since single patterning with an ArF immersion exposure tool reached its physical limit. Double patterning technology (DPT) is one of the promising techniques for 20nm technology node and beyond. 1 For Litho-Etch-Litho-Etch (LELE) process, whic h is one of the DPTs, layout design needs to be decomposed into two masks, usually utilizing graph theory.