Flexible Self-aligned Double Patterning Aware Detailed Routing with Prescribed Layout Planning

1. Flexible Self-aligned Double Patterning Aware DetailedRouting with Prescribed Layout Planning Jhih-RongGao and David Z. Pan ECE Dept. Univ. of Texas at Austin, Austin ISPD 2012

2. Outline • Introduction • Preliminaries • Algorithm • Experimental results • Conclusion

3. Introduction • DPL- LELE (litho-etch-litho-etch)- SADP (self-aligned double patterning) • LELE- allow stitch insertion to resolve conflict- much more overlay error than SADP

4. SADP- core mask and trim mask- good overlay controllability- no stitch allowed

6. Preliminaries • we propose a robust multi-layer SADP-aware detailed routing algorithm. • Our approach adopts the grid-based routing model. • We define the minimum width of mandrel pattern and trim pattern as Wmin. • We also assume that the width of sidewall spacer equals to Wmin. • A minimum spacing Sminmust be kept between any neighboring routing patterns. • For a legal layout decomposition result, patterns within the minimum DPL spacing Sdpmust be assigned to different types of pattern (mandrel pattern or trim pattern).

7. Algorithm • SADP-aware routing guidelines

9. Simultaneous layer assignment for conflict prevention

10. Overall flow

11. SADP-aware weighted cost

12. Neighborhood-based net orderingThis ordering method encourages nets within a certain distance to be routed in a sequence, so that the probability to provide spacer protection for these neighboring nets can be increased.

13. Experimental results

15. Conclusion • Anovel multi-layer SADP-aware detailed routing approach. • Solve routing and layout decomposition simultaneously based on the correct-by-construction approach. • Incorporate layer assignment to resolve potential pattern conflicts, which increases the flexibility of layout decomposition for SADP. • Present a set of SADP-aware routing guidelines, which helps improve the pattern quality of SADP.