Electrochemical-control of abrasive polishing and machining rates
AssigneeThe John Hopkins University
InventorsTimothy P. Weihs, Adrian B. Mann, Peter C. Searson
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Abstract
An apparatus and method is disclosed; both of which use electrochemistry to selectively grow and remove hard oxide coatings on metals, and capacitive double layers on non-metals and semiconductors in order to predict and control the rate of surface abrasion during planarization of the surface of such materials.
Claims6
A method of treating a surface of material on a silicon wafer, the method comprising the steps of:
- placing the silicon wafer in an electrolytic bath;
- placing reference and counter electrodes in the electrolytic bath;
- connecting a working electrode to the material on the silicon wafer to be planarized;
- applying a voltage to the working electrode so as to control growth and removal of a wear surface layer formed on the material;
- and
- planarizing the material and the wear surface layer formed on the material.
A system for using chemo-mechanical polishing (CMP) to planarize a surface of a metal interconnect applied during fabrication of an integrated circuit upon a silicon wafer, the system comprising:
- an electrolytic bath, wherein the silicon wafer is immersed in said electrolytic bath during CMP;
- an abrasive pad, wherein said abrasive pad applies a mechanical force on the surface of the metal interconnect while immersed in the electrolytic bath during CMP;
- a polishing slurry, said polishing slurry being immersed in the electrolytic bath, and being applied to a surface of the metal interconnect;
- and
- a power source applying a controlled voltage to said electrolytic bath during CMP, said power source further comprising:
- a working electrode coupled to the surface of the metal interconnect;
- a reference electrode, said reference electrode being immersed in the electrolytic bath;
- and
- a counter electrode, said counter electrode being immersed in the electrolytic bath;
- wherein the controlled voltage is applied across said working and reference electrodes as increased and decreased voltages to respectively facilitate growth and removal of a polishing surface layer formed on the surface of the metal interconnect during CMP.
Dependencies are inferred from the claim text.