Patent · US Active

Non-destructive wafer-scale sub-surface ultrasonic microscopy employing near field AFM detection

US8322220B2 · kind B2 · utility

9Cited by
9References
34Claims
0Family size

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Key dates

Filing dateMay 12, 2008
Grant dateDec 4, 2012
Priority date—
Expiry dateJun 29, 2031

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG01Q60/32
  • WIPO fieldMeasurement
  • WIPO sectorInstruments

Abstract

A method, and corresponding apparatus, of imaging sub-surface features at a plurality of locations on a sample includes coupling an ultrasonic wave into a sample at a first lateral position. The method then measures the amplitude and phase of ultrasonic energy near the sample with a tip of an atomic force microscope. Next, the method couples an ultrasonic wave into a sample at a second lateral position and the measuring step is repeated for the second lateral position. Overall, the present system and methods achieve high resolution sub-surface mapping of a wide range of samples, including silicon wafers. It is notable that when imaging wafers, backside contamination is minimized.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.