Characterization Vehicle Infrastructure And Defect Analyzer Integrated For In-Fab Defect Analysis

Hillsboro, OR - FEI Company and PDF Solutions, Inc. jointly announced the successful integration of PDF Solutions Characterization Vehicle (CV) infrastructure (CVi) and FEI's Defect Analyzer (DA) 300HP next-generation DualBeam system for automated in-fab defect analysis. The first combined solution was recently delivered to a global, U.S.-based developer and foundry of advanced microprocessor devices.

The new integrated flow accelerates yield ramps of deep sub-micron semiconductors by speeding root cause analysis of defects. This gives customers better control over advanced processes along with improved yields, reduced time-to-market, and significantly reduced process development costs. In the integrated flow, PDF Solutions short-flow CV test chips are run through the factory, where electrical tests are performed to identify non-visual, subsurface failures. Once the CV analysis software identifies failures, it works in conjunction with the voltage contrast capabilities of the FEI DA 300HP to precisely localize the failures (both opens and shorts) on the wafer to within a fraction of a micron. Defects are then automatically cross-sectioned by the DA 300HP, resulting in a detailed sub-surface image of the relevant failure location and of the failing structure. The image enables engineers to more rapidly and accurately identify the cause failures and validate potential process changes to determine those that reduce failure-rates to an acceptable level.

"As recognized in the yield roadmap outlined in the latest International Technology Roadmap for Semiconductors (ITRS), capturing, identifying, analyzing, and resolving non-visual defects and yield-detracting systematic mechanisms are major challenges faced by the semiconductor industry," said professor Andrzej Strojwas, chief technologist at PDF Solutions. "Having participated in more than 30 deep sub-micron process development and ramp projects—more than 12 at the 90nm to 45nm nodes—PDF Solutions recognized that working with FEI could help to successfully address these challenges."

PDF Solutions addresses the challenges of non-visual defects through its CVi, which provides a comprehensive set of test chip designs that contain a broad range of experiments aimed at identifying process-design yield sensitivities. The short-flow CV test chips are combined with a parallel fast tester and dedicated analysis software. The CVi greatly reduces the time to identify yield detractors and to evaluate potential process fixes. This is because manufacturing a short-flow CV test chip requires only a fraction of the 90 or more days required to manufacture and electrically test a full-flow product wafer.

"At FEI we understand our customers' requirements to rapidly acquire three dimensional defect data and images," commented Matt Harris, vice president of worldwide marketing for FEI. "By integrating the DA 300HP with the PDF Solutions CVi, we are providing our customers even faster access to that data."

FEI's DA 300HP is a highly automated in-fab 300 mm DualBeam (FIB/SEM) that is critical for yield-limiting defect identification, in-line module qualification, and defect and process marginality correlation. Utilizing Automatic Defect Redetection and Cross-Sectioning (ADR/ADX) along with Slice and View™, the DA 300HP is able to provide statistically significant root cause data. The FEI DA 300HP brings 3D defect diagnostics into semiconductor fabs to rapidly deliver critical process data and keep processes in control.

Traditional methods of defect cross sectioning—where failures are identified on a product or an SRAM wafer that is then sent offsite for analysis—has introduced a bottleneck in the sequence of yield improvement activities. The DA 300HP helps eliminate such bottlenecks by combining voltage contrast and defect cross sectioning in one tool, and enabling customers to perform these critical activities faster on the manufacturing floor. The new methodology is designed to reduce failure analysis time by several days compared with traditional flows.

SOURCE: PDF Solutions