In-situ monitoring and control of conductive films by detecting changes in induced eddy currents
AssigneeInternational Business Machines Corporation
InventorsLeping Li, Steven George Barbee, Arnold Halperin, Tony Frederick Heinz
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Abstract
The change in thickness of a film on an underlying body such as a semiconductor substrate is monitored in situ by inducing a current in the film, and as the thickness of the film changes (either increase or decrease), the changes in the current are detected. With a conductive film, eddy currents are induced in the film by a generating an alternating electromagnetic field with a sensor which includes a capacitor and an inductor.
Claims12
A method of controlling, in-situ and in real time, the removal of a conductive film from an underlying body using a removal process, the method comprising the steps of:
- (a) inducing eddy currents in the conductive film;
- (b) detecting a change in the eddy currents due to the removal of a portion of the conductive film;
- and
- (c) adjusting the removal process based upon the change detected,
- said inducing, detecting and adjusting steps being performed during the removal process, thereby providing real-time control of the removal process.
A method of monitoring, in-situ and in real time, an increase in thickness of a conductive film on an underlying body, the method comprising the steps of:
- (a) inducing an eddy current in the film with a sensor proximate the film;
- and
- (b) detecting a change in the current due to the change in thickness of the film,
- said inducing and detecting steps being performed during the change in thickness of the film, thereby providing real-time monitoring of the change in thickness of the film.
A method of controlling, in-situ and in real time, formation of a conductive film on an underlying body using a formation process, the method comprising the steps of:
- (a) inducing eddy currents in the conductive film;
- (b) detecting a change in the eddy currents due to an increase in thickness of the conductive film;
- and
- (c) adjusting the formation process based upon the change detected,
- said inducing, detecting and adjusting steps being performed during the formation process, thereby providing real-time control of the formation process.
Dependencies are inferred from the claim text.