The Microlithography Simulation Microscope, MSM 100, together with the Aerial Image Measurement Software, AIMS™, is designed to aid in the development, quality control, repair verification, and defect classification of phase-shift masks through the use of aerial image measurement. In addition, chrome masks can be inspected at stepper wavelengths, therefore, enhancing the quality of the analysis. The goal is to accelerate testing of the masks prior to the costly and time consuming step of wafer processing.

Phase-shift technology, in combination with G-line, I-line and DUV steppers, is one of the most promising steps to improve design rules pushing the geometries down to 0.35 micron and below.
In order to verify the mask performance and test the complex transmission patterns, under conditions identical to a stepper, the MSM 100 is optimized for G-line (436 nm), I-line (365 nm) and DUV (248 nm) 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 1.0. 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 through-focus images are then analyzed and displayed in various forms to give the user a much needed insight and understanding of the mask performance.

If you have any suggestions and/or requests please contact [email protected].