Elimination of Photoresist Linewidth Slimming by Fluorination

摘要

Typically resist performance has lagged behind exposure tools as new, shorter wavelengths are introduced in the never-ending industry quest to print smaller features. Over time, however, the performance improves until it matches or exceeds that of the resists used in the previous wavelength node; 193 nm resists have not been the exception. Their resolution and stability has improved but one issue that remains is linewidth slimming. This phenomenon consists in a reduction of resist features when the they are exposed to an electron beam in an scanning electron microscope during linewidth metrology. Although this phenomenon has been well described and reasonably well understood, no solution exists to eliminate this problem. In this paper we show linewidth slimming can be significantly reduced by fluorinating the resist after the relief image has been developed, keeping the lithographic dimensions unchanged.