18 October 2016 Process highlights to enhance directed self-assembly contact patterning performances
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We focus on the directed self-assembly (DSA) for contact hole (CH) patterning application using polystyrene-b-poly(methyl methacrylate) (PS-b-PMMA) block copolymers (BCPs). By employing the DSA planarization process, we highlight the DSA advantages for CH shrink, repair, and multiplication, which are extremely needed to push forward the limits of currently used lithography. Meanwhile, we overcome the issue of pattern density-related defects that are encountered with the commonly used graphoepitaxy process flow. Our study also aims to evaluate the DSA performances as functions of material properties and process conditions by monitoring main key manufacturing process parameters: CD uniformity (CDU), placement error (PE), and defectivity [hole open yield (HOY)]. Concerning process, it is shown that the control of surface affinity and the optimization of self-assembly annealing conditions enable significant enhancement of CDU and PE. Regarding material properties, we show that the best BCP composition for CH patterning should be set at 70/30 of PS/PMMA total weight ratio. Moreover, it is found that increasing the PS homopolymer content from 0.2% to 1% has no impact on DSA performances. Using a C35 BCP (cylinder-forming BCP of natural period L0=35  nm), good DSA performances are achieved: CDU -3σ = 1.2  nm, PE-3σ = 1.2  nm, and HOY = 100%. Finally, the stability of DSA process is also demonstrated through the process follow-up on both patterned and unpatterned surfaces over several weeks.
© 2016 Society of Photo-Optical Instrumentation Engineers (SPIE)
Ahmed Gharbi, Ahmed Gharbi, Raluca Tiron, Raluca Tiron, Maxime Argoud, Maxime Argoud, Gaëlle Chamiot-Maitral, Gaëlle Chamiot-Maitral, Antoine Fouquet, Antoine Fouquet, Céline Lapeyre, Céline Lapeyre, Patricia Pimenta-Barros, Patricia Pimenta-Barros, Florian Delachat, Florian Delachat, Sandra Bos, Sandra Bos, Shayma Bouanani, Shayma Bouanani, Xavier Chevalier, Xavier Chevalier, Célia Nicolet, Célia Nicolet, Christophe Navarro, Christophe Navarro, Ian Cayrefourcq, Ian Cayrefourcq, Laurent Pain, Laurent Pain, } "Process highlights to enhance directed self-assembly contact patterning performances," Journal of Micro/Nanolithography, MEMS, and MOEMS 15(4), 043503 (18 October 2016). https://doi.org/10.1117/1.JMM.15.4.043503 . Submission:

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