Inspection Methods

• A 400 x microscope, .25µm resolution, with 0.1µm resolution encoding. Encoding error is ‹0.25µm up to 0.5mm range, not to exceed 0.75 micron over 100mm range. The encoding on this system may be used for any aperture features over 2.5µm. Smaller features, ‹2.5µm, utilize primarily the microscope’s calibrated reticle which can resolve 0.25 µm. On features ›100 microns the encoding is always used to calibrate or certify a measurement. Features ‹100 µm are subject to measurement by reticle after verifying the reticle’s calibration with the encoding system.
• A 1000 x microscope is used on aperture features from 2.5µm to give a more positive view and about .18µm resolution
• A Deltronic DH214-MPC-5 Comparator, accuracy 0.0002 inch, may be used in measuring larger substrates or backers from .5 to 8.0 inch.

Our microscope inspection equipment is regularly calibrated against a chrome on glass photo mask standard with +/-0.2µm accuracy over 3 inches square. This plate is inspected but inspection errors are added. The original plot is done to +/-0.2µm accuracy.