MX 204-8-21-V


Thickness, TTV, Bow, Warp


  • Automatic wafer geometry gauge
  • Wafer diameter 6" and 8"
  • Thickness range 100 - 700µm
  • Accuracy 1µm
  • Resolution 0.1µm
  • Software MXNT

Warp and Bow-bf do not include gravity correction

Measurement Principle

The thickness and warp measurements are performed in two consecutive stages.

In the first stage, the warp measurement, the upper probe head is in the raised position, the air gap between the probe heads is wide, and the wafer is resting freely on the surface of the lower probe head. Only the distance sensors of the lower probe head are used for measuring. The wafer shape measured under these conditions meets the Japanese definition of Sori. Another quite intuitive set of wafer characteristics is provided by the local distances between the lower probe plate and the lower wafer surface, respectively the local maximum among these.

For the second stage, the thickness measurement, the wafer is chucked to the surface of the lower probe head, and the upper probe head is lowered so the air gap is narrow. This enhances the precision of thickness measurements. The capacitive sensors in both probe heads measure the respective distances between the probe head surfaces and the wafer.

If there is foil applicated onto the wafer, the foil must be of high quality and its characteristics must be known by the PC-software.