Apparatus and method for radio frequency de-coupling and bias voltage control in a plasma reactor
First Claim
1. A plasma processing chamber, comprising:
- a bottom electrode configured to hold a substrate;
a first and a second radio frequency (RF) power supply being connected to the bottom electrode;
a passive top electrode being electrically isolated from a top ground extension;
a filter array defining a set of filtering settings; and
a switch being coupled to the top electrode and the filter array, the switch being configured to interconnect the top electrode to a selected one of the set of filtering settings, the selection of one of the filtering settings being configured to substantially enable or disable RF current generated from one or both of the first RF power supply and the second RF power supply from passing through the top electrode.
1 Assignment
0 Petitions
Accused Products
Abstract
Provided is a method and apparatus for controlling a bias voltage over a wide range and for de-coupling dual radio frequency (RF) currents to allow for independent control of plasma density and ion energy of a plasma for processing a substrate. An exemplary apparatus provides a plasma processing chamber which includes a bottom electrode configured to hold a substrate and first and second RF power supplies being connected to the bottom electrode. Also included is a top electrode which is electrically isolated from a top ground extension. A filter array defining a set of filter settings is included. A switch is coupled to the top electrode and the switch is configured to interconnect the top electrode to one of the filter settings. The filter settings are configured to enable or disable RF current generated from one or both of the RF power supplies from passing through the top electrode.
-
Citations
27 Claims
-
1. A plasma processing chamber, comprising:
-
a bottom electrode configured to hold a substrate;
a first and a second radio frequency (RF) power supply being connected to the bottom electrode;
a passive top electrode being electrically isolated from a top ground extension;
a filter array defining a set of filtering settings; and
a switch being coupled to the top electrode and the filter array, the switch being configured to interconnect the top electrode to a selected one of the set of filtering settings, the selection of one of the filtering settings being configured to substantially enable or disable RF current generated from one or both of the first RF power supply and the second RF power supply from passing through the top electrode. - View Dependent Claims (2, 3, 4, 5, 6, 24)
a first control for modulating power to the first RF power supply, the first control being configured to control an ion energy of a plasma; and
a second control for modulating power to the second RF power supply, the second control being configured to control a plasma density.
-
-
5. The plasma processing chamber as recited in claim 1, further comprising,
a bottom ground extension, the bottom ground extension being coupled to the bottom electrode through a quartz insulator. -
6. The plasma processing chamber as recited in claim 2, wherein the RF current passing through each of the top ground extension and the bottom ground extension returns to the first and second power supplies.
-
24. The plasma processing chamber as recited in claim 1, wherein the filter settings are selected from the group consisting of a low pass filter, a high pass filter, and an ultra low pass filter.
-
7. An etch system having selectable modes of operation, comprising:
-
a radio frequency (RF) driven electrode, the RF driven electrode being configured to accept a first and a second RF current provided by a first and a second RF generator;
a passive electrode defined over the RF-driven electrode to define a plasma region therebetween, the passive electrode being electrically floating;
confinement rings extending from a top surface of the RF driven electrode to a bottom surface of the passive electrode;
a filter array including multiple filter settings; and
a selector switch associated with one of the multiple filter settings, the selector switch being configured to enable passage of one, both or none of the first and second RF currents through the passive electrode according to the one of the multiple filter settings. - View Dependent Claims (8, 9, 10, 11, 12, 13, 25)
a first control for modulating power to the first RF generator, the first control being configured to control an ion energy of a plasma in the plasma region; and
a second control for modulating power to the second RF generator, the second control being configured to control a plasma density.
-
-
25. The etch system as recited in claim 7, wherein the multiple filter settings are selected from the group consisting of no filter, a low pass filter, a high pass filter, and an ultra low pass filter.
-
14. An apparatus for de-coupling dual frequencies used in plasma etching, comprising:
-
a plasma etch reactor, the plasma etch reactor including a bottom electrode and a top electrode, a first and second radio frequency (RF) power supply being connected to the bottom electrode, the top electrode being electrically isolated from a top ground extension integrated around the top electrode, the top and bottom electrode defining a plasma region;
a first RF current return path to the first and second power supplies, the first return path passing through the top electrode;
a second RF current return path to the first and second power supplies, the second return path passing through a the top ground extension without passing through the top electrode; and
a selector switch, the selector switch being configured to block one, both or substantially none of the RF currents from the first RF currant return path. - View Dependent Claims (15, 16, 17, 18, 26)
a set of filter settings associated with the selector switch, wherein selection of one of the set of filter settings through the selector switch determines an area ratio between the top electrode and the bottom electrode.
-
-
19. An apparatus for etching a substrate, comprising:
-
a first and second power supply, the first and second power supplies being configured to deliver radio frequency (RF) currents to a bottom electrode;
a top electrode, the top electrode defining a first return path to the power supply;
a filter array associated with the top electrode;
a top and a bottom ground extension, the top and bottom ground extensions defining a second and a third return path to the power supplies; and
a selector switch, the selector switch having selectable modes of operation, wherein one, all or substantially none of the RF currents are blocked from the first return path. - View Dependent Claims (20, 21, 22, 23, 27)
-
Specification