New Antireflective Coating Materials Containing a Novel Chromophore for KrF Laser Lithography

摘要

Implementation of bottom anti-reflective coatings (BARC) is increasingly wide-spread in advanced microlithograpic processes to suppress and eliminate the problems associated with reflection such s swing effects and reflective notching, thereby improving critical dimension (CD) control and process latitude.[1,2,3] In addition, the use of BARC beneath the deep UV resist greatly reduces possible CD variations caused by reflection and scattered light from substrate topography as well as the subtle chemical and physical problems associated with the underlying substrate-photoresist interface such as contamination effects, substrate etching due to developer attack and so on. The BARC materials are designed to match the basic optical properties such as refractive index (n) and absorbance (k),in partivular, a high absorption characteristic at the exposure wavelength in principle.[4,5,6] For the practical applications in deep UV lithography, they should have high plasma-etch rates bearing high etch selectivity between the BARC and photoresist layers as well as compatibility with the various types of known chemical amplification photoresists by means of the fine tuning the BARC formulations for optimal lithographic performance. [7,8,9].