Metal Charge layer for SEM measurements ,optical defect inspection, laser and FIB defect Repair and Defect protection_
Original Publication Date: 2000-Nov-01
Included in the Prior Art Database: 2003-Jun-18
Title of disclosure Metal Charge layer for SEM measurements ,optical defect inspection, laser and FIB defect Repair and Defect protection Idea of disclosure Measurement of high end products in optical mask manufacture is limited by the ability of optical microscopes to resolve below .7 microns and to measure accurately. It is required today to use SEM measurements on features that are smaller than .7 microns to gain repeatable and accurate results. This technique to date is destructive because of defects generated in non clean room SEM areas and is extremely inaccurate unless a charge dissipating layer is applied to the surface being analyzed. Stripping the charging layer can degrade the mask and create additional defects. Due to this degrade caused by strip the part must go to an inspection tool to locate any additional defects. If clear (missing material) defects are found the plate must again be coated with a conductive layer so processing with a focused ion beam (FIB) repair system can occur without charging. In addition, adding a charge neutralizing layer to a production part renders the part useless to typical defect detection systems that find defects in the plate utilizing transmitted light.