Inventors at Georgia Tech have developed a positive-tone resist as a novel solution to current problems in integrated circuits industry. It is based on a rational design of molecular glass resist materials, which can form cross-linked networks resulting in a higher modulus and glass transition temperature (Tg). Network cleavage can be induced through an acid-catalyzed depolymerization in a patternwise fashion in exposed or unexposed regions upon exposure to external stimuli, such as ultraviolet light. This cleavage results in a relief structure formed in the resist upon development in a solvent. Such molecular resists can be designed by incorporating crosslinkable chemical groups with an un-reactive core, which are then either physically blended with a photoacid generator (PAG) or covalently bound to a PAG within the same molecule to generate a single-component resist. The inventors have demonstrated a model compound, THPE-2VE, that can be thermally crosslinked to form an insoluble network. Upon exposure to deep-ultraviolet (DUV) light at 248 nm, it demonstrates superior performance compared to conventional polymeric resists and previously developed depolymerization resists.
- Requires less energy
- Higher mechanical strength
- No base quencher needed
- Rreducing concerns from LER, photoacid blur and solvent swelling
- Improved homogeneity and patterning performance
- Due to smaller pixel size and higher crosslink density
- Extreme ultraviolet (EUV) lithography
- Microelectronics fabrication processes
- Generating patterns for integrated circuits
- Microelectronic devices:
- Flash memory
- Semiconductor chips
As chip manufacturers continue to shrink their integrated circuits, design and production of photoresists become challenging due to issues that affect their performance, such as line edge roughness (LER), photoacid blur, and pattern collapse. Crosslinked polymeric resists offer better mechanical and thermal properties to prevent pattern collapse and photoacid blur compared to uncrosslinked polymers. However, they still suffer from inhomogeneity in the blended film that causes LER.