Influence of process parameters on the lithographic performance characterization in the top imaging process by silylation

摘要

Single level dry developable resist process based on gas phase silylation has great promise for sub-halfmicron pattern imaging due to shallow exposure, which leads to a thin silicon incorporation layer during silylation process in the top exposed region. In this paper the influence of process key parameters on the lithographic performance characterization has been investigated. For this experiment, two kinds of commercial i-line photoresists based upon novolac-diazoquinone and tetramethyldisilazane as a silylation agent were used for analyzing the process properties. As a result, it was observed that the ultimate resolution of 0.30 $mu@m with vertical profiles, projected with an i-line of 0.54 NA lens, was obtained. However, it was found that CD linearity characteristics strongly depend on the compositions and the structure of photoresist, independent of other process parameters. Selectivity of dry development with a range of 13 - 15 was achieved using the oxygen/argon mixtures at 5 mTorr with MERIE. Major factors affect on the resist pattern profile were proven to be dry development parameters as well as the latent image formation of silylation. In particular, lower power and higher magnetic field conditions at low pressure allowed a good resist pattern profile without sidewall roughness and residues. And effects of silylation parameters on process latitudes has also been studied by comparing resolution capability, DOF, and exposure latitude, respectively.