Product History

1
Product History
WX, ZX, EX sensors required multiple gain
adjustments for robust detection
2
Why did we build the EX-Q?

• Wanted a sensor that could provide
• Consistent wafer detection without frequent gain
  adjustments
• "Through beam like" performance
• Backward compatibility with existing EX sensors
• Maintaining flexible, off-the-shelf package of a
  reflective sensor

3
What's required for accurate wafer mapping?

• Any mapping sensor (regardless of technology)
  must have consistent and accurate Apparent Wafer
  Thickness for reliable mapping performance
• Apparent Wafer Thickness the scan distance
  between the beginning (ON) pulse and the end
  (OFF) pulse of the sensor's output signal

4
How did we do it?

• Reduced the thickness of the laser stripe to
  0.05mm while maintaining peak response
  (sensitivity)
• Reduces the laser stripe's skirt or "noise" to
  provide a more accurate, consistent AWT

5
EX-Q Performance vs. Wafer Reflectivity

• EX-Q maintains consistent Apparent Wafer
  Thickness regardless of wafer reflectivity

Max/Min Range Expect gt99.8 of sensor
measurements to be within Max/Min range
Mapping Algorithm Safety Region Able to classify
absent, present, cross slot
6
Detecting future wafers

• EX-Q has the sensitivity and detection headroom
  to detect ultra thin and/or other wafers with
  extreme characteristics

Detection Headroom (on axis)
gt 1000X
gt 100X
gt 100X
gt 10X
Threshold signal detection (data normalized to 1)
7
EX-Q doesn't need gain adjustments

• EX-Q delivers both detection and accurate AWT at
  the factory gain setting for most wafer types
  or, all SEMI standard wafers
• EX required a trade-off between detection and AWT
  which demanded gain adjustments in the field as a
  function of wafer type

8
Vertical tilt results in stray reflection
immunity

• EX-Q sensors have a 3 vertical tilt integrated
  into the sensor to avoid FOUP back reflections

9
EX-Q Improvements
10
Backwards Compatibility

• Upgrading is easy and convenient
• EX-Q sensors have the same mechanical footprint,
  electrical interface and digital output as the EX
  and WX
• Plug-and-play compatible with existing software
  algorithms for the EX, requiring only reteaching
  the robot at setup
• Upgrading from the WX requires reteaching the
  robot at setup and appropriate parameter
  adjustment