Method and apparatus for monitoring and controlling force applied on workpiece surface during electrochemical mechanical processing
AssigneeASM Nutool, Inc.
InventorsBulent M. Basol, Jeffrey A. Bogart, Efrain Velazquez
Life of this patent
Estimating the term…
Abstract
In one aspect, the present invention monitors a signal corresponding to a torque value of a motor that is used to maintain relative motion between a conductive top surface of a workpiece and a workpiece surface influencing device in the presence of physical contact between the conductive top surface of the workpiece and the workpiece surface influencing device. In another aspect, the present invention uses the signal to control a force applied to a top conductive surface of a workpiece during electrotreatment.
Claims51
A method of monitoring force applied to a top conductive surface of a workpiece during an electrotreatment process that operates upon the conductive surface using an electrotreatment solution, the method comprising the steps of:
- performing an electrotreatment process on the conductive surface using a potential difference created between the conductive surface and an electrode during at least a portion of the electrotreatment process and the electrotreatment solution disposed between a workpiece surface influencing device and the conductive surface of the workpiece, the electrotreatment process including maintaining relative motion between the workpiece surface influencing device and the conductive surface of the workpiece in the presence of physical contact between the workpiece surface influencing device and the conductive surface of the workpiece, whereby the relative motion in the presence of the physical contact cause the force between the workpiece surface influencing device and the conductive surface of the workpiece;
- and
- monitoring a signal obtained that corresponds to a torque value of a motor that is used to maintain the relative motion in the presence of the physical contact during the electrotreatment process.
A method of operating upon a plurality of wafers each having a conductive surface using an electrotreatment solution comprising the steps of:
- initializing an electrotreatment process, the step of initializing the electrotreatment process including obtaining a displacement between the conductive surface of each wafer and a workpiece surface influencing device that are in physical contact;
- performing an electrotreatment process on the conductive surface of a first group of the plurality of wafers using a potential difference created between the conductive surface of each wafer and an electrode during at least a portion of the electrotreatment process with the presence of the electrotreatment solution, the electrotreatment process including maintaining relative motion between the workpiece surface influencing device and the conductive surface of the workpiece in the presence of the displacement;
- reinitializing an electrotreatment process, the step of reinitializing the electrotreatment process including obtaining a reinitialized displacement;
- and
- performing the electrotreatment process on the conductive surface of a second group of the plurality of wafers using the potential difference created between the conductive surface of each wafer and the electrode during at least a portion of the electrotreatment process with the presence of the electrotreatment solution, the electrotreatment process including maintaining relative motion between the workpiece surface influencing device and the conductive surface of the workpiece in the presence of the reinitialized displacement amount.
An apparatus for monitoring force applied on a top conductive surface of a wafer during an electrotreatment process that uses an electrotreatment solution, comprising:
- an electrode;
- an electrotreatment dispenser for dispensing the electrotreatment solution;
- a workpiece surface influencing device disposed between the top conductive surface and the electrode;
- means for creating a potential difference between the electrode and the top conductive surface in the presence of the electrotreatment solution;
- a device adapted to provide for relative movement of the wafer with respect to the workpiece surface influencing device in the presence of physical contact between the top conductive surface and the workpiece surface influencing device while the electrotreatment solution is disposed between the top conductive surface and the workpiece surface influencing device and while the potential difference between the electrode and the top conductive surface is maintained;
- and
- a monitoring system adapted to monitor a frictional force occurring between the top conductive surface and the workpiece surface influencing device.
Dependencies are inferred from the claim text.