Wafer‐Level Self‐Organized Copolymer Templates for Nanolithography with Sub‐50 nm Feature and Spatial Resolutions

Abstract

Robust lithographic templates, with sub-50 nm feature and spatial resolutions, that exhibit high patterning integrity across a full-wafer are demonstrated using self-organized copolymer reverse micelles on 100 mm Si wafers. A variation of less than 5% in the feature size and periodicity of polymeric templates across the entire wafer is achieved simply by controlling the spincoating process. Lithographic pattern transfer using these templates yields Si nanopillar arrays spanning the entire wafer surface and exhibiting high uniformity inherited from the original templates. The variation in geometric characteristics of the pillar arrays across the full-wafer surface is validated to be less than 5% using refl ectance spectroscopy. The physical basis of the change in refl ectance with respect to sub-10 nm variations in geometric parameters of pillar arrays is shown by theoretical modelling and simulations. Successful fabrication of highly durable TiO 2 masks for nanolithography with sub-50 nm feature width and spatial resolutions is achieved through highly controlled vapour phase processing of reverse micelle templates. This allows lithographic pattern-transfer of organic templates with a feature thickness and separation of less than 10 nm, which is otherwise not possible through other approaches reported in literature.

Azopolymer‐based micro‐ and nanopatterning for photonic applications

“…It is provided by azobenzene‐containing block copolymers . These materials have great future prospects, since they combine the possibility of optical patterning and controlling the block‐copolymer self‐assembly with the immense potential of the block copolymers in microfabrication and nanofabrication …”

Gold nanoparticle density-multiplication by tuning block copolymer self-assembly processes toward increased charge storage

“…21,37 Thus, an extension of the particle density multiplication process obtained by tuning the pitch of the templates will aim at filling up the void between the arrays with nanoparticle clusters of smaller sizes through a systematic hierarchical self-assembly approach. While the results establish a definite trend in the particle density enhancement with the increase in the density of the polymer templates, each of the nanocluster arrays exhibits a tolerable error in the density as a result of standard deviation (B5%) in the separation of polymer features characteristic to the block copolymer selfassembly process.…”

Development of a facile block copolymer method for creating hard mask patterns integrated into semiconductor manufacturing

“…Dielectric materials (SiO2, Al2O3 and Si3N4 etc. ), various metal oxides and metals have been used as 'hard' etch masks [31][32][33][34] because of their etch resistance relative to silicon. However, they require complex, multi-step pattern transfer processes from the pre-fabricated patterns.…”

“…[31] Metals (Cr, Ni), are somewhat limited in use, particularly for small feature sizes, as they are usually patterned by a lift-off technique but this can result significant distortion of the patterns and metal etching can present challenges. [32][33][34][35] It should be recognized that advances in etch mask materials coupled to development of facile process at lower cost, could be important for the economics of the semiconductor and other patterning industries. [36][37] Thus, our work on pattern transfer using iron oxide masks might have real relevance since it combines simple, controlled self-assembly with an 'insitu' hard mask technique.…”