Creative Use of Vector Scan for Efficient SRAM Inspection

Abstract

A simple way to gain 3 to 5x throughput for SRAM E-beam inspection (EBI) through innovative application of Vector Scan Technology is described. EBI, despite many unique advantages, is limited by throughput. Vector Scan technology, developed for patterning weak point inspection, allows hot spots within a very large field of view (FOV) to be scanned, thereby saving both move time plus time wasted on uninteresting pixels. This technology was adapted for VC inspection of SRAM, a common yield driver vehicle, at GLOBALFOUNDRIES for the development of a recent technology, providing an effective throughput gain of 4.2x, for three heavily used inspections.