Directed self-assembly (DSA) has the potential to extend scaling for both line/space and hole patterns. DSA has shown the capability for pitch reduction (multiplication), hole shrinks, CD self-healing as well as a pathway towards line edge roughness (LER) and pattern collapse improvement [1][2][3][4]. The current challenges for industry adoption are materials maturity, practical process integration, hardware capability, defect reduction and design integration. Tokyo Electron (TEL) has created close collaborations with customers, consortia and material suppliers to address these challenges with the long term goal of robust manufacturability.This paper provides a wide range of DSA demonstrations to accommodate different device applications. In collaboration with IMEC, directed line/space patterns at 12.5 and 14 nm HP are demonstrated with PS-b-PMMA (poly(styrene-b-methylmethacrylate)) using both chemo and grapho-epitaxy process flows. Pre-pattern exposure latitudes of >25% (max) have been demonstrated with 4X directed self-assembly on 300 mm wafers for both the lift off and etch guide chemo-epitaxy process flows. Within TEL's Technology Development Center (TDC), directed selfassembly processes have been applied to holes for both CD shrink and variation reduction. Using a PS-b-PMMA hole shrink process, negative tone developed pre-pattern holes are reduced to below 30 nm with critical dimension uniformity (CDU) of 0.9 nm (3σ) and contact edge roughness (CER) of 0.8 nm (3σ). To generate higher resolution beyond a PS-b-PMMA system, a high chi (χ) material is used to demonstrate 9 nm HP line/ space post-etch patterns. In this paper, TEL presents process solutions for both line/space and hole DSA process integrations.

Determination of the optimal double patterning scheme depends on cost, integration complexity, and performance. This paper will compare the overall CDU performance of litho-etch-litho-etch (LELE) versus a spacer approach. The authors use Monte Carlo simulation as a way to rigorously account for the effect of each contributor to the overall CD variation of the double patterning process. Monte Carlo simulation has been applied to determine CD variations in previous studies 1-2 , but this paper will extend the methodology into double patterning using a calibrated resist model with topography.

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