Thickness sensor for conductive features
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorsChih Hung Chen, Kei-Wei Chen, Ying-Lang Wang
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Abstract
Various embodiments provide a thickness sensor and method for measuring a thickness of discrete conductive features, such as conductive lines and plugs. In one embodiment, the thickness sensor generates an Eddy current in a plurality of discrete conductive features, and measures the generated Eddy current generated in the discrete conductive features. The thickness sensor has a small sensor spot size, and amplifies peaks and valleys of the measured Eddy current. The thickness sensor determines a thickness of the discrete conductive features based on a difference between a minimum amplitude value and a maximum amplitude value of the measured Eddy current.
Claims20
A device, comprising:
- an Eddy current reader configured to measure Eddy currents induced in a plurality of conductive features on a substrate, and generate an Eddy current signal based on the measured Eddy currents;
- and
- a processor configured to calculate a thickness value representing a thickness of the conductive features based on a difference between a maximum amplitude value of the Eddy current signal and a minimum amplitude value of the Eddy current signal.
A device, comprising:
- an Eddy current reader configured to measure Eddy currents in a plurality of conductive features on a substrate, and generate an Eddy current signal based on the measured Eddy currents;
- and
- a processor configured to receive the Eddy current signal, determine a maximum amplitude value of the Eddy current signal, determine a minimum amplitude value of the Eddy current signal, and calculate a thickness value representing a thickness of the conductive features based on the maximum amplitude value and the minimum amplitude value.
A device, comprising:
- an Eddy current reader configured to measure first Eddy currents in a first plurality of conductive features, and generate a first Eddy current signal based on the measured first Eddy currents;
- and
- a processor configured to determine a reference amplitude value based on a minimum amplitude value of the first Eddy current signal, and calculate a thickness value representing a thickness of the first plurality of conductive features based on the reference amplitude value.
Dependencies are inferred from the claim text.