×

Apparatus and method for characterizing semiconductor wafers during processing

  • US 5,996,415 A
  • Filed: 04/30/1997
  • Issued: 12/07/1999
  • Est. Priority Date: 04/30/1997
  • Status: Expired due to Term
First Claim
Patent Images

1. An improved apparatus for characterizing a substrate, comprising:

  • a plurality of pin transducers, each having a probe end configured to couple acoustic energy between the pin transducer and the substrate and a transducer end configured to convert the acoustic energy in the pin transducer to external electrical signals and vice-versa;

    a first set of the pin transducers including a transmitting pin configured so that the transducer end of the transmitting pin when coupled to a signal pulse of a predetermined character, excites pin acoustic waves in the pin that the probe end of the transmitting pin couples into the substrate as substrate acoustic waves;

    a second set of the pin transducers including one or more receiving pins configured so that the transducer end of a respective receiving pin produces a transmitted electrical signal representing the acoustic energy in a transmitted wave coupled from the substrate to the respective pin by that pin'"'"'s probe end in response to arrival at that probe end of the substrate acoustic waves; and

    acquisition and processing modules configured to perform a characterization measurement wherein;

    the acquisition module is configured to (1) receive the transmitted electrical signal during a measuring period following the signal pulse; and

    (2) digitize the received transmitted signals; and

    the processing module is configured to (3) digitally compute from the digitized, received transmitted signals a respective measurement set correlated to spectral frequency components of the substrate acoustic waves.

View all claims
  • 4 Assignments
Timeline View
Assignment View
    ×
    ×