System for coupling a voltage to portions of a substrate
The present disclosure generally relates to plasma assisted or plasma enhanced processing chambers. More specifically, embodiments herein relate to electrostatic chucking (ESC) substrate supports configured to provide independent pulses of DC voltage through a switching system to electrodes disposed through the ESC substrate support, or to electrodes disposed on a surface of the ESC, or to electrodes embedded in the ESC substrate support. The switching system can independently alter the frequency and duty cycle of the pulsed DC voltage that is coupled to each electrode. During processing of the substrate, the process rate, such as etch rate or deposition rate, can be controlled independently in regions of the substrate because the process rate is a function of the frequency and duty cycle of the pulsed DC voltage. The processing uniformity of the process performed on the substrate is improved.
1. A substrate support assembly, comprising:
a substrate support configured to support a substrate;
a cooling base disposed below the substrate support;
a plurality of electrodes extending through the substrate support and exposed at an upper surface of the substrate support, wherein each electrode is configured to contact the substrate, wherein each electrode is fixed or movably coupled to the cooling base, wherein each electrode is connected to a pair of switches, and wherein each switch has a switch frequency of about 1 MHz; and
a chucking electrode planarly embedded in the substrate support.
2. The substrate support assembly of claim 1 , wherein the plurality of electrodes is a plurality of conductive pins.
3. The substrate support assembly of claim 1 , wherein an electrode of the plurality of electrodes comprises aluminum, an aluminum alloy, silicon carbide, or combinations thereof.
4. The substrate support assembly of claim 1 , wherein each switch of the pair of switches is a fast high-voltage transistor switch.
5. The substrate support assembly of claim 1 , wherein one of the pair of switches is connected to a voltage source of a first polarity, and another pair of switches is connected to a voltage source of a second polarity.
6. The substrate support assembly of claim 5 , wherein the first polarity is the opposite of the second polarity.
7. The substrate support assembly of claim 1 , wherein the plurality of electrodes is arranged in a circular pattern.
8. The substrate support assembly of claim 1 , wherein the pair of switches has coordinated cyclic timing, and wherein a frequency of the coordinated cyclic timing is 1 kHz or greater.
9. A substrate support assembly, comprising:
a substrate support configured to support a substrate;
a cooling base disposed below the substrate support;
a plurality of bias electrodes extending through the substrate support and exposed at an upper surface of the substrate support, wherein each electrode is configured to contact the substrate, wherein each electrode is fixed or movably coupled to the cooling base, wherein each bias electrode is connected to a pair of switches, and wherein each switch has a switch frequency of about 1 MHz; and
an electrostatic chucking electrode planarly embedded in the substrate support.
10. The substrate support assembly of claim 9 , wherein each switch of the pair of switches is a fast high-voltage transistor switch.
11. The substrate support assembly of claim 9 , wherein one of the pair of switches is connected to a voltage source of a first polarity, and another pair of switches is connected to a voltage source of a second polarity.
12. The substrate support assembly of claim 11 , wherein the first polarity is the opposite of the second polarity.
13. The substrate support assembly of claim 9 , wherein the pair of switches has coordinated cyclic timing, and wherein a frequency of the coordinated cyclic timing is 1 kHz or greater.
14. The substrate support assembly of claim 9 , wherein the plurality of bias electrodes comprises a circular plate and one or more discontinuous annuluses that are concentric with the circular plate.
15. The substrate support assembly of claim 9 , wherein the plurality of bias electrodes is arranged in a spoke pattern, grid pattern, line pattern, spiral pattern, interdigitated pattern, random pattern, or combinations thereof.
16. The substrate support assembly of claim 9 , wherein the plurality of bias electrodes is isolated from each other.
17. A processing chamber, comprising:
a chamber lid;
one or more sidewalls;
a chamber bottom, wherein the chamber lid, the one or more sidewalls, and the chamber bottom define a processing volume; and
a substrate support assembly disposed in the processing volume, the substrate support assembly comprising;
a cooling base;
a substrate support configured to support a substrate and coupled to the cooling base;
an electrostatic chucking electrode planarly embedded in the substrate support; and
a plurality of bias electrodes extending through the substrate support and exposed at an upper surface of the substrate support, wherein each electrode is configured to contact the substrate, wherein each electrode is fixed or movably coupled to the cooling base, wherein each bias electrode is connected to a pair of switches, and wherein each switch has a switch frequency of about 1 MHz.
18. The processing chamber of claim 17 , wherein the where one of the pair of switches is connected to a voltage source of a first polarity, and another pair of switches is connected to a voltage source of a second polarity.
19. The processing chamber of claim 18 , where the first polarity is the opposite of the second polarity.
20. The processing chamber of claim 17 , wherein the pair of switches has coordinated cyclic timing, and wherein a frequency of the coordinated cyclic timing is 1 kHz or greater.