KLA-Tencor Corp. said Monday (Nov. 21) that it has identified a new application for its MicroLoop electrical defect detection methodology that can detect critical bridging defects on advanced flash memory wafers nearly twice as fast as current methods.
KLA (San Jose, Calif.) said the new application was developed through collaboration with Spansion LLC's Fab 25 in Austin, Texas. As a result of the development, KLA said, Spansion has deployed the MicroLoop methodology in conjunction with KLA's eS31 electron-beam inspection system in the production of its 90-nanometer MirrorBit technology and its 110-nm NOR flash technology.
"KLA-Tencor's MicroLoop methodology uses state-of-the-art technology for monitoring flash memory devices on layers with layouts that mimic standard MicroLoop test structures, enabling us to apply the MicroLoop methodology on product wafers without having to engage in additional test chip design or utilize test wafers," said Alfredo Herrera, contamination free manufacturing manager for Spansion's Fab 25. "In addition to achieving greater inspection throughput, the combination of MicroLoop and the eS31 provided enhanced sensitivity to unique killer defects, which we were able to identify as electrical shorts."
By adding the MicroLoop methodology to an eS31 inspection strategy, KLA said, fabs can reduce time to root-cause identification of front-end-of-line (FEOL) and back-end-of-line (BEOL) yield-limiting defects by 50 percent.
MicroLoop methodology is typically implemented through the integration of customized test structures with e-beam inspection and on-board defect analysis, but can be used for flash memory development without test chips, KLA said, saving substantial time.
"The rapid lifecycles associated with many of today's consumer electronics products have placed enormous pressure on our customers to speed their time- to-market in order to achieve their profitability goals," said Mike Kirk, vice president of KLA's wafer inspection group, in a statement. "This is driving us to work more closely with key customers, like Spansion, to develop solutions and best practices that enable them to ramp up their yields higher and faster. Even shaving off a few weeks from our customers' yield-learning cycle times can translate into millions of dollars in additional revenue for them through earlier market penetration."