Microelectronic Engineering 67–68 (2003) 283–291 www.elsevier.com / locate / mee Resist process issues related to the glass transition changes in chemically amplified resist films a, a a a a a * I. Raptis , D. Niakoula , E. Tegou ,V. Bellas , E. Gogolides , P. Argitis , b c K.G. Papadokostaki , A. Ioannidis a Institute of Microelectronics NCSR ‘‘ Demokritos’’ 15310 Ag. Paraskevi Attikis, Greece b Institute of Physical Chemistry NCSR ‘‘ Demokritos’’ 15310 Ag. Paraskevi Attikis, Greece c ‘‘ Xenon’’, Delfon 15 Chalandri, 15233 Attikis, Greece Abstract Optical interferometry is applied for in situ measurement of the glass transition temperature in thin resist films film ( T ) spin-coated on flat reflective substrates, using a novel, low-cost, rapid methodology. Process issues, such g film as film thickness and thermal processing effect on T were explored using this methodology. In the case of g film relatively thick films the calculated T from the optical interferometry method is in good agreement with the g film corresponding differential scanning calorimetry (DSC) values. The film thickness effect on T in the case of g two positive chemically amplified resists (one commercial for DUV and one experimental for 157 nm film lithography) is studied and discussed. In both cases, as film thickness decreases the T increases indicating g strong surface phenomena that should be taken into account in lithographic processing. The presented methodology enabled studies on T changes during resist processing in characteristic positive and negative tone g chemically amplified resist materials allowing deeper insight in resist optimization issues.  2003 Elsevier Science B.V. All rights reserved. Keywords: Glass transition temperature; Optical interferometry; Polymers; Thin films; Lithography; Resists 1. Introduction As the dimensions of integrated circuits continue to shrink, new lithographic methods / tools are applied in the research and the fabrication of advanced devices. According to the International Technology Roadmap for Semiconductors [1], the longterm lithographic requirements for year 2010 will be 45 nm lateral dimensions using EUV and / or 157 nm lithography. Nevertheless, exposure tools, resists and masks should be available earlier. Due to the absorbance issues at 157 nm and EUV *Corresponding author. E-mail address: raptis@imel.demokritos.gr (I. Raptis). 0167-9317 / 03 / $ – see front matter  2003 Elsevier Science B.V. All rights reserved. doi:10.1016 / S0167-9317(03)00080-7