Method for electroplating metal films including use a cathode ring insulator ring and thief ring
AssigneeAIWA Research and Development, Inc.
InventorJane Ang
Life of this patent
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Abstract
Multiple-layer thin film devices are deposited by electroplating on an otherwise substantially clean substrate wafer. The composition of the electroplated alloy layers is maintained substantially uniform using a cathode assembly on which the substrate wafer is mounted. The cathode assembly includes an inner cathode ring electrically connected to the wafer, a thief ring external to the cathode ring and an insulating ring connected between and electrically insulating the cathode and thief rings. The cathode ring and the thief ring are powered by separate power sources.
Claims17
A method of electroplating a thin metal film onto a substrate wafer comprising the steps of:
- electroplating on a clean substrate wafer in an electroplating solution;
- maintaining an alloy composition uniformity of at least one electroplated layer substantially uniform using a cathode assembly for mounting the substrate wafer, the cathode assembly including:
- an inner cathode ring electrically connected to the wafer;
- a thief ring external to the cathode ring;
- and
- an insulating ring connected between and electrically insulating the cathode and thief rings;
- and
- powering the cathode ring and the thief ring using separate first and second power sources having respective first and second negative terminals respectively coupled to the cathode ring and the thief ring the first and second power sources having a positive terminal coupled to an anode.
A method of electroplating a thin NiFe film onto a substrate wafer comprising the steps of:
- electroplating on a clean substrate wafer in an electroplating solution;
- maintaining a NiFe composition uniformity of at least one electroplated layer substantially uniform using a cathode assembly for mounting the substrate wafer, the cathode assembly including:
- an inner cathode ring electrically connected to the wafer;
- a thief ring external to the cathode ring;
- and
- an insulating ring connected between and electrically insulating the cathode and thief rings;
- powering the cathode ring and the thief ring using separate first and second power sources having respective first and second negative terminals respectively coupled to the cathode ring and the thief ring, the first and second power sources having a positive terminal coupled to anode;
- supplying a constant current to the cathode ring;
- and
- adjusting a current supplied to the thief ring in order to achieve a desired Fe composition on a particular portion of the wafer.
A method of electroplating a thin metal film onto a substrate wafer comprising the steps of:
- electroplating on a clean substrate wafer in an electroplating solution;
- maintaining an alloy composition uniformity of at least one electroplated layer substantially uniform using a cathode assembly for mounting the substrate wafer, the cathode assembly including:
- an inner cathode structure electrically connected to the wafer;
- a thief structure external to the cathode structure;
- and
- an insulating structure connected between and electrically insulating the cathode and thief structures;
- and
- powering the cathode structure and the thief structure using separate first and second and power sources having respective first and second negative terminals respectively coupled to the cathode ring and the thief ring, the first and second power sources having a positive terminal coupled to an anode.
Dependencies are inferred from the claim text.