A novel single-device DC method for extraction of the effective mobility and source-drain resistances of fresh and hot-carrier degraded drain-engineered MOSFET's

• Published in: IEEE transactions on electron devices 1998-06, Vol.45 (6), p.1317-1323
• Main Authors: Choon-Leong Lou, Wai-Kin Chim, Chan, D.S.-H., Tang Pan
• Format: Article
• Language: English
• Subjects: Current measurement; Degradation; Electrical resistance measurement; Failure analysis; Hot carrier effects; Hot carriers; Integrated circuit reliability; MOSFET circuits; Rain; Stress
• ISSN: 0018-9383; 1557-9646
• DOI: 10.1109/16.678559

A new DC technique, the drain current-conductance method (DCCM), has been developed to extract the gate bias dependent effective channel mobility (/spl mu//sub eff/), and source and drain series resistance (R/sub s/ and R/sub d/) of drain-engineered MOSFET's. The extraction of /spl mu//sub eff/, R/sub e/, and R/sub d/ by DCCM is based on the DC measurements of drain current and conductance of a single device. The negligible difference between the measured and modeled (using the extracted parameters) linear drain current showed that the DCCM is accurate and effective for devices with different graded junction structures and channel lengths. Asymmetry between R/sub s/ and R/sub d/ for LDD p-MOSFET's was found to be more significant than for LATID n-MOSFET's. This asymmetry has invalidated many methods which utilized the assumptions of R/sub d/=R/sub s/ for the extraction of device parameters. The DCCM was further applied to devices with nonuniform hot-carrier degradation. The /spl mu//sub eff/, R/sub s/, and R/sub d/ of LATID n-MOSFET's degraded under different hot-carrier stress conditions were extracted. The increase in R/sub d/ is found to dominate the initial phase of hot-carrier degradation while the decrease in /spl mu//sub eff/ intensifies as the stress duration increases. The extracted parameters have provided physical insight into the asymmetries of graded junctions and degradation mechanisms of hot-carrier stressed MOSFET's, The DCCM is especially useful for the extraction of SPICE parameters that are usable in circuit and reliability simulation.