International Business Machines Corporation

Tony F Heinz

Leping Li

Steven G Barbee

Eugene Henry Ratzlaff

Yiping Hsiao

Justin W Wong

Arnold Halperin

Victor J Silvestri

Madhav Datta

Ravindra V Shenoy

Justin Wai-chow Wong

Gary S Selwyn

Richard John Lebel

Michael J Balconi-Lamica

Syothi Singh

John A Spinetti, Jr

Ulrich Hofer

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.

In-situ monitoring and control of conductive films by detecting changes

A contactless method and apparatus for real-time in-situ monitoring of a chemical etching process during etching of at least one wafer in a wet chemical etchant bath are disclosed. The method comprises the steps of providing two conductive electrodes in the wet chemical bath, wherein the two electrodes are proximate to but not in contact with a wafer; monitoring an electrical characteristic between the two electrodes as a function of time in the etchant bath of the at least one wafer, wherein a prescribed change in the electrical characteristic is indicative of a prescribed condition of the etching process; and recording a plurality of values of the electrical characteristic as a function of time during etching. From the plurality of recorded values and corresponding times, instantaneous etch rates, average etch rates, and etching end points may be determined. Such a method and the apparatus therefor are particularly useful in a wet chemical etch station.

Real time measurement of etch rate during a chemical etching process

In-situ monitoring of the change in thickness of films

In-situ monitoring of conductive films on semiconductor wafers

A contactless method and apparatus for in-situ chemical etch monitoring of an etching process during etching of a workpiece with a wet chemical etchant are disclosed. The method comprises steps of providing at least two toroidal windings in the wet chemical etchant to be proximate to but not in contact with the workpiece; and monitoring an electrical characteristic between said at least two toroidal windings, wherein a prescribed change in the electrical characteristic is indicative of a prescribed condition of the etching process. Such a method and apparatus are particularly useful in a wet chemical etch station.

Apparatus for contactless real-time in-situ monitoring of a chemical

A contactless method and apparatus for real-time in-situ monitoring of a chemical etching process during etching of at least one wafer in a wet chemical etchant bath are disclosed. The method comprises the steps of providing two conductive electrodes in the wet chemical bath, wherein the two electrodes are proximate to but not in contact with a wafer; monitoring an electrical characteristic between the two electrodes as a function of time in the etchant bath of the at least one wafer, wherein a prescribed change in the electrical characteristic is indicative of a prescribed condition of the etching process; detecting a minimum and maximum value of the electrical characteristic during etching; determining the times of the minimum and maximum values; and comparing the times of the minimum and maximum values to determine a film etching uniformity value. Such a method and the apparatus therefor are particularly useful in a wet chemical etch station, and are useful for film deposition process quality control.

Chemical etch monitor for measuring film etching uniformity during a

A contactless method and apparatus for real-time in-situ monitoring of a chemical etching process for the etching of at least one wafer in a wet chemical etchant bath are disclosed. The method comprises the steps of providing at least two conductive electrodes in the wet chemical bath, wherein the at least two electrodes are proximate to but not in contact with the at least one wafer, and further wherein said two electrodes are positioned on the same side of the wafer; and monitoring an electrical characteristic between the at least two electrodes, wherein a prescribed change in the electrical characteristic is indicative of a prescribed condition of the etching process. Such a method and apparatus are particularly useful in a wet chemical etch station.

Contactless real-time in-situ monitoring of a chemical etching

A contactless method and apparatus for real-time in-situ monitoring of a chemical etching process to minimize overetch of at least one wafer in a wet chemical etchant bath are disclosed. The method comprises the steps of providing two conductive electrodes in the wet chemical bath, wherein the two electrodes are proximate to but not in contact with a wafer; monitoring an electrical characteristic between the two electrodes as a function of time in the etchant bath of the at least one wafer, wherein a prescribed change in the electrical characteristic is indicative of a prescribed condition of the etching process; detecting a minimum and maximum value of the electrical characteristic during etching; determining the times of the minimum and maximum values; and comparing the times of the minimum and maximum values to determine an overetch value. The overetch value may be compared to a desired value to control the etching process. Such a method and the apparatus therefor are particularly useful in a wet chemical etch station.

Minimizing overetch during a chemical etching process

Measuring film etching uniformity during a chemical etching process

Method for contactless real-time in-situ monitoring of a chemical

A contactless method and apparatus for in-situ chemical etch monitoring of an etching process during etching of a workpiece with a wet chemical etchant are disclosed. The method comprises steps of providing a base member having a reference surface; releasably securing the workpiece to the base member; providing at least two sensors disposed on the base member to be proximate to but not in contact with the outer perimeter of the workpiece surface; and monitoring an electrical characteristic between said at least two sensors, wherein a prescribed change in the electrical characteristic is indicative of a prescribed condition of the etching process.

Method and apparatus for contactless real-time in-situ monitoring of a

A fixture for in-situ chemical etch monitoring of an etching process during etching of at least one wafer contained in a wafer carrier is disclosed. The fixture comprises a set of primary guide members for engaging and guiding a front portion of the wafer carrier. A set of rear guide members engages and guides a rear portion of the wafer carrier. A set of electrode arms is included for receiving a respective electrode and corresponding electrode wire thereon. A mounting plate establishes a prescribed spacing of the set of primary guide members with respect to the set of electrode arms. A means for self-locking the first wafer contained in the wafer boat is connected to the mounting plate and further positioned in a prescribed manner with respect to the set of primary guide members and the set of electrode arms. Lastly, a connecting means connects the mounting plate, the set of primary guide members, and the set of electrode arms to the set of rear guide members, whereby insertion of the wafer boat into the fixture establishes a prescribed distance between the set of electrode arms and the first wafer, and further wherein the first wafer is passively fixed by the self-locking means.

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Chappaqua, NY, United States of America

Tony F Heinz