High-throughput parallel SPM for metrology, defect and mask inspection

Scanning probe microscopy (SPM) is a promising candidate for accurate assessment of metrology and defects on wafers and masks, however it has traditionally been too slow for high-throughput applications, although recent developments have significantly pushed the speed of SPM [1,2]. In this paper we present new results obtained with our previously presented high-throughput parallel SPM system [3,4] that showcase two key advances that are required for a successful deployment of SPM in high-throughput metrology, defect and mask inspection. The first is a very fast (up to 40 lines/s) image acquisition and a comparison of the image quality as function of speed. Secondly, a fast approach method: measurements of the scan-head approaching the sample from 0.2 and 1.0 mm distance in under 1.4 and 6 seconds respectively.