Proceedings Article | 16 April 2011
Proc. SPIE. 7972, Advances in Resist Materials and Processing Technology XXVIII
KEYWORDS: Lithography, Etching, Polymers, Reflectivity, Photoresist materials, Double patterning technology, Critical dimension metrology, Photoresist developing, Temperature metrology, Bottom antireflective coatings
As critical dimensions continue to shrink in lithography, new materials will be needed to meet the new demands
imposed by this shrinkage. Recently, there are needs for novel materials with various substrates and immersing process,
including double patterning process, a high resolution implant process, and so on. Among such materials, Developable
Bottom Anti-reflective Coating material (DBARC) is a good candidate for high resolution implant application as well as
double patterning. DBARC should have reflectivity control function as an ordinary BARC, as well as an appropriate
solubility in TMAH-based conventional developer after exposure and bake process. The most distinguished advantage of
DBARC is to skip BARC etch process that is required in normal BARC process. In spite of this advantage, the
photoresist profile on DBARC could be influenced by components and process conditions of DBARC. Several groups
have tried to solve this issue to implement DBARC to new process.
We have studied material-related factors affecting photoresist profiles, such as a polymer, photo-acid generators
(PAGs), and additives. And we explored the effect of process condition for photoresist and DBARC. In case of polymer,
we studied the effect of dissolution rate in developer and crosslinking functionality. For PAGs and additives, the effect
of acid diffusivity and cross-linking degree according to their bulkiness were examined. We also evaluated coated film
stability in a photoresist solvent after BARC bake process and compared lithographic performance of various DBARC
formulations. In addition, the effect of photoresist profile with bake condition of photoresist and DBARC were
investigated. In this paper, we will demonstrate the most influential factors of DBARC to photoresist profile and
suggest the optimum formulation and process condition for DBARC application.
