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 LWR and pattern collapse improvement [1-10]. TEL has developed a DSA development ecosystem (collaboration with customers, consortia, inspection vendors and material suppliers) to successfully demonstrate directed PS-PMMA DSA patterns using chemo-epitaxy (lift-off and etch guide) and grapho-epitaxy integrations on 300 mm wafers. New processes are being developed to simplify process integration, to reduce defects and to address design integration challenges with the long term goal of robust manufacturability. For hole DSA applications, a wet development process has been developed that enables traditional post-develop metrology through the high selectivity removal of PMMA cylindrical cores. For line/ space DSA applications, new track, cleans and etch processes have been developed to improve manufacturability. In collaboration with universities and consortia, fundamental process studies and simulations are used to drive process improvement and defect investigation. To extend DSA resolution beyond a PS-PMMA system, high chi materials and processes are also explored. In this paper, TEL’s latest process solutions for both hole and line/space DSA process integrations are presented.
In this paper we report on the patterning challenges for the integration of Spin-Transfer Torque Magneto-Resistive- Random-Access Memory (STT MRAM). An overview of the different patterning approaches that have been evaluated in the past decade is presented. Plasma based etching, wet echting, but also none subtractive pattering approaches are covered. The paper also reports on the patterning strategies, currently under investigation at imec.
Directed Self-Assembly (DSA) has become a promising alternative for generating fine lithographic patterns. Since contact holes are among the most difficult structures to resolve through traditional lithographic means, directed selfassembly applications that generate smaller contact holes are of particular interest to the industry. In this paper, DSA integrations that shrink pre-patterned contact holes were explored. The use of both block copolymers (BCPs)1 and blended polymer systems2 was considered. In addition, both wet3 and dry4 techniques were used to develop the central core out of the respective phase-separated morphologies. Finally, the hole patterns created through the various contact hole applications were transferred to substrates of interest with the goal of incorporating them into an IMEC 28 nm node via chain electrical test vehicle for direct, side-by-side comparison.