Observation of Swelling Behavior of ArF Resist during Development by using QCM Method (2)

Abstract

Many reports have discussed the swelling behavior of photoresists during development, as observed by the QCM method. Previously, we reported on the development of development analysis equipment based on the QCM method. In this paper, we report on a high-precision resist development analyzer also based on the QCM method. This equipment incorporates a high-precision developing solution temperature controller and features a high-precision air conditioning function for the measurement chamber. We also measured swelling behavior during development using a TBAH developer solution, which features larger molecules than TMAH, comparing these results with those obtained with TMAH. The results of this measurement indicate that the extent of resist swelling during development is less with TBAH developer solution than with TMAH developer solution. This result is consistent with results of a study by Itani et al. using high-speed AFM, suggesting the suitability of the measurement equipment used in our experiments.

Diagnosing phenomena that influence missing contacts and pillars

“…Many QCM studies of resist materials have been made and there is little evidence of swelling of PHS materials. Measuring initial responses on a QCM at a small fraction of a second is challenging due to an additional frequency shift caused by to the heat shock during the introduction of the solvent Sekiguch et al 19 . Horumoto et al 20 showed a thick transient swelling layer for acrylic resist while PHS showed little swelling.…”

Spatially-resolved dissolution monitoring using AFM

“…For example the quartz crystal microbalance (QCM) technique, 5 has been used to measure the dissolution response of photoresist exposed to clear-field or unpatterned radiation, showing a brief swelling of the resist before its rapid removal. 6 Similarly, Itani et al performed AFM experiments measuring the dissolution response of patterned resist materials, and also observed swelling prior to removal of the exposed material. 7 This swelling my be a significant contributor to LER, and has been cited as a motivating factor in the search for novel developers, including a tone-switch by using solvent developer 8 .…”