Microlithography Simulation Microscope

Featured at Semicon Europa

The Microlithography Simulation Microscope (MSM) 193, together with the Aerial Image Measurement Software (AIMS), aids in the development, quality control, repair verification, and defect classification of masks through the use of aerial image measurements. The goal is to accelerate testing of the masks prior to wafer processing, yielding improvement and cost reduction in the mask making process.

Phase shift technology, in combination with 193 nm optical lithography is one of the more promising techniques to improve design rules pushing the geometries down to 0.13 µ and below. In order to verify the mask performance and test the complex transmission patterns under conditions identical to a stepper, the MSM 193 is optimized for the ArF-line (193nm) exposure. In addition, the user can control the numerical aperture (NA) and the degree of coherence (SIGMA) based on the stepper in use. Both the illumination and imaging apertures can be viewed for alignment, allowing the precise setting and control of the partial coherence ratio from 0.1 to 0.8. The aperture planes are user accessible for various aperture sizes and shapes, including off-axis illumination.

The AIMS software provides the user with complete system control, image acquisition, and analysis. The mask is positioned by a precision motorized stage under the microscope objective. A series of aerial images is captured as a function of focus at a high magnification by a UV CCD camera system. These thorough-focus images are then analyzed and displayed in various forms to give the user insight and understanding of the mask performance. Further analysis may be performed by entering the aerial image data collected with the MSM 193 into commercially available resist simulation packages, enabling comparison with mask design data and measurements.

Carl Zeiss. D-07740. Jena Tel: 49 (0) 3641 64 2909. Fax: 49 (0) 3641 64 3144