Method and apparatus for detecting defects in wafers
January 23, 2018. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent ReferencesAutomatic photomask inspection system and apparatus Scanning contaminant and defect detector System for contactless testing of multi-layer ceramics System for contactless electrical property testing of multi-layer ceramics Inspection of multilayer ceramic circuit modules by electrical inspection of green specimens Method and apparatus for analyzing semiconductor devices using charge-sensitive electron-beam-injected-carrier microscopy Emission microscopy system Particle detection method including comparison between sequential scans Method and apparatus for detecting defects in repeated microminiature patterns Particle detection on patterned wafers and the like InventorsApplicationNo. 012277 filed on 01/23/1998US Classes:324/751, Using electron beam probe324/750, System sensing fields adjacent device under test (DUT)324/754, With probe elements324/765Test of semiconductor deviceExaminersPrimary: Brown, Glenn W.Attorney, Agent or FirmForeign Patent References
International ClassesG01R 031/305G01R 031/02 AbstractA method for detecting electrical defects in a semiconductor wafer, includes the steps of: a) applying charge to the wafer such that electrically isolated structures are raised to a voltage relative to electrically grounded structures; b) obtaining voltage contrast data for at least a portion of the wafer containing such structures using an electron beam; and c) analyzing the voltage contrast data to detect structures at voltages different from predetermined voltages for such structures. Voltage contrast data can take one of a number of forms. In a simple form, data for a number of positions on a line scan of an electron beam can be taken and displayed or stored as a series of voltage levels and scan positions. Alternatively, the data from a series of scans can be displayed as a voltage contrast image. Analysis can be achieved by comparison of one set of voltage contrast data, for example voltage contrast data from one die on a wafer, with one or more other such sets, for example voltage contrast data for corresponding structures on one or more preceding dice, so as to determine differences therebetween.Other References
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