19 May 2008 Phame: phase measurements on 45nm node phase shift features
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Proceedings Volume 7028, Photomask and Next-Generation Lithography Mask Technology XV; 70282Z (2008) https://doi.org/10.1117/12.793105
Event: Photomask and NGL Mask Technology XV, 2008, Yokohama, Japan
The extension of optical lithography to the 45nm node and beyond goes along with increased mask complexity and tightening of specifications. The proper use of PSM becomes more and more important and the phase shift needs to be quantified exactly in order to achieve accurate CD printing results during wafer processing. The methods currently available run into limitations because they are not able to consider diffraction limitations caused by scanner NA and mask pitch, as well as 3D mask effects. In the transition to the 45nm node and beyond, these effects play an important role and need to be considered. Zeiss' new phase metrology system Phame® captures diffraction limitations, rigorous effects (i.e., a failure of the Kirchhoff approximation), and polarization effects. The new phase metrology system measures the phase shift in any in-die feature of the active mask area for on- and off-axis applications with high spatial resolution. This paper is focused on through pitch and through duty cycle measurements on an alternating PSM. Phame® measurements will be compared to AFM measurements. Additionally rigorous 3D simulations have been performed for different CD, varying pitch and varying duty cycle using coherent illumination with polarization. The simulation results will be compared to Phame® measurement results.
© (2008) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Ute Buttgereit, Robert Birkner, Dirk Seidel, Sascha Perlitz, Vicky Philipsen, Peter De Bisschop, "Phame: phase measurements on 45nm node phase shift features", Proc. SPIE 7028, Photomask and Next-Generation Lithography Mask Technology XV, 70282Z (19 May 2008); doi: 10.1117/12.793105; https://doi.org/10.1117/12.793105

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