|
The LMS-2000 Laser Metrology system is a micro-image dimensional analysis system designed to meet the mask and reticle metrology needs of present and future semiconductor IC designs. The need for improved metrology is driven by the continued advance of micro-lithographic fabrication technology toward the half-micron design rules. The resolution, accuracy, and repeatability of the LMS-2000 system are consistent with the mask and reticle metrology requirements for these design rules. In order to achieve the required 30 nanometer accuracy and the 20 nanometer repeatability for metrology, many factors must be taken into account which have been disregarded in existing metrology systems. These factors relate to a variety of error corrections for the laser interferometer used and the careful control of temperature affecting the measurement. The accuracy and repeatability of the LMS-2000 system result from the capabilities built into the optical scanner used to detect line edges; the interferometer controlled stage and associated calibration and correction techniques; and finally the careful treatment of potential temperature effects affecting measurement accuracy and precision. In addition, throughput, automation, and user friendliness are key attributes which have been incorporated into the LMS-2000 dimensional analysis system.
|
