Patent ID: 7264676

Claim:
A plasma apparatus capable of adaptive impedance matching, comprising: a plasma reactor which produces plasma to proceed with chemical vapor deposition process; a bi-polar electrostatic chuck which locates inside said plasma reactor to support and secure a wafer and said bi-polar electrostatic chuck has an inner electrode and an outer electrode; an alternating current bias power which connects to said inner electrode and said outer electrode, and said alternating current bias power provides the bias for ion-bombardment on said wafer; and an impedance matching circuit, said impedance matching circuit connects between said alternating bias power, said inner electrode and said outer electrode of said bi-polar electrostatic chuck in order to balance a power output of said inner electrode power and a power output of said outer electrode and said impedance matching circuit includes a plurality of adjustable inductors, wherein a first terminal of said plurality of adjustable inductors connects to an external circuit and a second terminal of said plurality of adjustable inductors connects to an alternating current bias power; a plurality of adjustable capacitors, wherein a first terminal of said plurality of adjustable capacitors connects to a second terminal of said plurality of inductors and a second terminal of said plurality of adjustable capacitors connects to the ground; a power-measuring device which connects to said second terminal of said plurality of adjustable inductors to measure the power outputs of said second terminal of said plurality of adjustable inductors; a power comparator which connects to said power-measuring device and produces a control signal for automatic impedance regulation; and an automatic impedance-regulator which connects with said plurality of adjustable inductors, said plurality of adjustable capacitors, and said power comparator, wherein said automatic impedance-regulator receives said control signal for automatic impedance regulation to regulate the impedance values of said plurality of adjustable inductors and the impedance values of said plurality of adjustable capacitors.