Technology Path-finding for Directed Self-Assembly for Via Layers

Directed Self Assembly (DSA) is a very promising patterning technology for the sub-inm technology nodes, especially for via/contact layers. In the Graphoepitaxy type of DSA, a complementary lithography technique is used to print the guiding templates, where the Block Copolymer (BCP) phase-separates into regular structures. Accordingly, the design-friendliness of a DSA-based technology is affected by several factors: the complementary lithography technique, the legal guiding templates, the number of masks/exposures used to print the templates, the related design rules, the forbidden patterns (hotspots) and the characteristics of the BCP. Titus, foundries have a huge number of choices to make fora future OSA-based technology, affecting; the design-friendliness and the cost of the technology. In this paper, we propose a framework for DSA technology with finding, for via layeN, to be used by the foundry as part of Design and 'Technology Co optimization(1)TC0). The framework optimally evaluates a DSA-based technology where an arbitrary lithography technique is used to print the guiding templates, possibly using many masks/exposures and provides a design-friendliness metric. The framework is used to evaluate technologies like DSA+193nm Immersion (193i) Lithography, DSA+Extreme Ultraviolet (EUV) and DSA+ Self-Aligned Double Patterning. For example, one study showed that one mask of EUV in a DSA+EUV technology can replace three masks of 193i in a DSA+193i technology.