EEtimes – JSR Corp., along with its U.S. operations, JSR Micro Inc., have rolled out a new directed self-assembly (DSA) technology for the sub-20-nm half-pitch node. Developed as part of an ongoing research agreement with IBM Corp., the new technology eliminates dual exposure steps and is compatible with conventional 193-nm lithography equipment.
ACS Nano – Simple and Versatile Methods To Integrate Directed Self-Assembly with Optical Lithography Using a Polarity-Switched Photoresist paper from June, 2010 is an example of some of the work on Directed Self-Assembly
The paper describes novel strategies to integrate block copolymer self-assembly with 193 nm water immersion lithography. These strategies employ commercially available positive tone chemically amplified photoresists to spatially encode directing information into precise topographical or chemical prepatterns for the directed self-assembly of block copolymers. Each of these methods exploits the advantageous solubility and thermal properties of polarity-switched positive tone photoresist materials. Precisely registered, sublithographic self-assembled structures are fabricated using these versatile integration schemes which are fully compatible with current optical lithography patterning materials, processes, and tooling.
Directed Self Assembly is an emerging technology, that to-date has been primarily driven by research efforts in university and corporate laboratory environments. Through these environments, we have seen many promising demonstrations including small half pitch (less than 15nm), registration control, and various layout shape capabilities. Now, the attention turns to integrating these capabilities into a 300mm pilot fab, which can study the directed self-assembly in the context of the semi-conductor fabrication environment and equipment set. This body of work discusses the status and challenges observed during a 300mm pilot fab implementation study.
Directed self-assembly for lithography applications
Directed self-assembly (DSA), which combines self-assembled polymers and substrates with lithographically-defined directing prepatterns, has been considered as a potential candidate to extend the resolution limit of conventional lithography. Frequency multiplication and pattern rectification have been successfully demonstrated using block copolymers on patterned substrates defined by electron-beam, EUV or 193nm lithography have been demonstrated. In this paper, we investigate materials, directing prepatterns, and their interactions using experiments and simulations. Track-compatible DSA process and materials provide a simple and straight forward DSA platform to generate sub-lithographic line-space patterns and vias with precise placement and better CD uniformity.
Polymer blends for patterning applications
Self-aligned double patterning (SADP) is one prominent scheme to extend 193 nm immersion lithography; however, the numerous inorganic material deposition and etch transfer steps significantly increase the cost of SADP schemes. Therefore, an SADP process based capable of forming spacers using a spin-on material and typical wafer track processing would eliminate a significant amount of process complexity and cost.