Detailed routing for spacer-is-metal type self-aligned double/quadruple patterning lithography

Abstract

As the technology nodes scale down to 22nm and beyond, Double Patterning Lithography (DPL) has been considered as a practical solution for manufacturing process. Compared with Litho-Etch-Litho-Etch (LELE), Self-Aligned Double Patterning (SADP) has better overlay tolerance. Two types of SADP process are popularly used for the state-of-the-art lithography patterning: Spacer-Is-Dielectric (SID) and Spacer-Is-Metal (SIM). Meanwhile, Self-Aligned Quadruple Patterning (SAQP), as a natural extension of SADP, is expected to be one of the major solutions for future process requirement after the 16nm/14nm technology node. In order to have better decomposability of layout patterns, we consider SIM type SADP/SAQP during detailed routing stage. The idea of color pre-assignment is adopted and a graph model is proposed which greatly simplifies the problem and reduces design rule violation. Then, the negotiated congestion based scheme is applied for detailed routing based on our proposed graph model. Compared with other state-ofart works, our approach does not produce any side overlay error and no design rule violation is reported. Meanwhile, a better solution in terms of total wirelength, via count, routability, and runtime is achieved.

Toward Unidirectional Routing Closure in Advanced Technology Nodes

“…To date, manufacturing-friendly detailed routing studies follow the paradigms of sequential routing [11], [13], [28], [37], [45], [46] and negotiation-congestion-based routing technique [8], [9]. When a router accesses an I/O pin locally, it creates a routing interval pattern on M2 for the net connection as shown in Fig.…”

“…Most existing manufacturing-friendly studies focus on the coloring scheme of routing patterns while leveraging SAMP-specific manufacturing constraints [8], [9], [11], [13], [28], [37], [45], c 2017 Information Processing Society of Japan [46], [57], [68]. Reference [45] presents the first SADP-aware detailed routing study by considering SADP-specific constraints during sequential routing procedure.…”

“…Reference [9] proposes a novel graph model to capture the SADP-specific manufacturing constraints and delivers SADP-friendly routing results with negotiation-congestion-based routing scheme. References [37] and [8] further enhance the graph model for better results by considering overlay constraints and via model, respectively. These studies aforementioned rely on two-dimensional patterns, which contradicts with the pure unidirectional routing style in advanced technology nodes.…”

“…10 (d). Despite wirelength overhead, our recent routing study demonstrates that, by incorporating the results from routing interval generation and assignment, a negotiation-congestion-based router can obtain much better routing results, i.e., unidirectional routing closure, than state-of-the-art manufacturing-friendly routing studies [8], [68]. Specifically, compared to sequential routing with pin access planning schemes [68], our proposed approach obtains over 15% wirelength reduction and over 10X runtime speed-up.…”

“…Compared to a pure negotiation-congestion-based routing scheme without routing interval generation and assignment [8], our approach achieves over 14% via number reduction and over 2X runtime speed-up.…”