Device and method for determining wafer bow
AssigneeTokyo Electron Limited
InventorsDaniel Fulford, Mark I. Gardner, Henry Jim Fulford, Anton Devilliers
Life of this patent
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Abstract
An apparatus for measuring bow of a wafer, includes a substrate holder having a support surface configured to support a wafer; and a capacitor array unit including a plurality of electrodes laterally spaced from one another in the capacitor array unit. Each electrode faces the support surface and is spaced a respective fixed distance from the support surface such that each electrode can form a capacitor with an opposing area of a substrate provided on the support surface of the substrate holder.
Claims20
An apparatus for measuring bow of a wafer, comprising:
- a substrate holder having a support surface configured to support a wafer;
- and
- a capacitor array unit comprising a plurality of electrodes laterally spaced from one another in the capacitor array unit, each electrode facing the support surface and being spaced a respective fixed distance from the support surface such that each electrode forms a capacitor with an opposing area of a substrate provided on the support surface of the substrate holder.
A method of measuring wafer bow comprising:
- providing a plurality of electrodes each facing a respective area of a wafer surface such that the electrode and respective area form a capacitor;
- measuring a capacitance value at each electrode;
- calculating a distance from each electrode to its respective area based on the measured capacitance at the respective electrode;
- and
- determining a bow of the wafer based on the calculated distances.
Dependencies are inferred from the claim text.