Control of wafer bow in multiple stations

Patent metadata

Field	Value
Publication number	US-11823928-B2
Application number	US-202117515261-A
Country	US
Kind code	B2
Filing date	Oct 29, 2021
Priority date	Jul 25, 2016
Publication date	Nov 21, 2023
Grant date	Nov 21, 2023

Abstract

A system for controlling of wafer bow in plasma processing stations is described. The system includes a circuit that provides a low frequency RF signal and another circuit that provides a high frequency RF signal. The system includes an output circuit and the stations. The output circuit combines the low frequency RF signal and the high frequency RF signal to generate a plurality of combined RF signals for the stations. Amount of low frequency power delivered to one of the stations depends on wafer bow, such as non-flatness of a wafer. A bowed wafer decreases low frequency power delivered to the station in a multi-station chamber with a common RF source. A shunt inductor is coupled in parallel to each of the stations to increase an amount of current to the station with a bowed wafer. Hence, station power becomes less sensitive to wafer bow to minimize wafer bowing.

First claim

The invention claimed is:

1. A method comprising:
receiving, by a plurality of low frequency paths, a low frequency modified radio frequency (RF) signal to output a plurality of low frequency RF signals;
receiving, by a plurality of high frequency paths, a high frequency modified RF signal to output a plurality of high frequency RF signals;
combining, by a plurality of output paths, the plurality of low frequency RF signals and the plurality of high frequency RF signals to output a plurality of combined signals to a plurality of plasma processing stations; and
controlling, by a plurality of shunt inductors, a plurality of amounts of current of the plurality of combined signals provided to the plurality of plasma processing stations, wherein each of the plurality of shunt inductors is coupled to a corresponding one of the plurality of low frequency paths.

2. The method of claim 1 , wherein said receiving the low frequency modified RF signal includes:
receiving the low frequency modified RF signal at a low frequency input; and
splitting, at the low frequency input, the low frequency modified RF signal into a plurality of input signals.

3. The method of claim 2 , further comprising:
processing, by a plurality of inductors and a plurality of capacitors of one of the plurality of low frequency paths, one of the plurality of input signals to output a processed signal, wherein said controlling the plurality of amounts of current includes modifying an amount of current of the processed signal to output one of the plurality of low frequency signals.

4. The method of claim 1 , wherein said receiving the high frequency modified RF signal includes:
receiving the high frequency modified RF signal at a high frequency input; and
splitting, at the high frequency input, the high frequency modified RF signal into a plurality of input signals.

5. The method of claim 4 , further comprising:
processing, by a plurality of capacitors of one of the plurality of high frequency paths, one of the plurality of input signals to output one of the plurality of high frequency RF signals.

6. The method of claim 1 , wherein said combining the plurality of low frequency RF signals and the plurality of high frequency RF signals to output the plurality of combined signals to the plurality of plasma processing stations comprises:
combining a first one of the plurality of low frequency RF signals with a first one of the plurality of high frequency RF signals to output a first one of the plurality of combined signals to a first one of the plurality of plasma processing stations;
combining a second one of the plurality of low frequency RF signals with a second one of the plurality of high frequency RF signals to output a second one of the plurality of combined signals to a second one of the plurality of plasma processing stations.

7. The method of claim 1 , wherein the plurality of shunt inductors include a first shunt inductor and a second shunt inductor, wherein the plurality of amounts of current include a first amount of current and a second amount of current, wherein the plurality of plasma processing stations include a first plasma processing station and a second plasma processing station, wherein the plurality of combined signals include a first combined signal and a second combined signal, wherein said controlling, by the plurality of shunt inductors, the plurality of amounts of current provided to the plurality of plasma processing stations comprises:
modifying a first inductance of the first shunt inductor to change the first amount of current provided to the first plasma processing station; and
modifying a second inductance of the second shunt inductor to change the second amount of current provided to the second plasma processing station.

8. A method comprising:
receiving, by a plurality of low frequency paths, a low frequency modified radio frequency (RF) signal to output a plurality of low frequency RF signals;
receiving, by a plurality of high frequency paths, a high frequency modified RF signal to output a plurality of high frequency RF signals;
combining, by a plurality of output paths, the plurality of low frequency RF signals and the plurality of high frequency RF signals to output a plurality of combined signals to a plurality of plasma processing stations; and
controlling, by a plurality of shunt inductors, a plurality of amounts of current of the plurality of combined signals provided to the plurality of plasma processing stations, wherein each of the plurality of shunt inductors is coupled to a corresponding one of the plurality of output paths.

9. The method of claim 8 , wherein said receiving the low frequency modified RF signal includes:
receiving the low frequency modified RF signal at a low frequency input;
splitting, at the low frequency input, the low frequency modified RF signal into a plurality of input signals; and
processing, by a plurality of capacitors and a plurality of inductors of one of the plurality of lower frequency paths, one of the plurality of input signals to output one of the plurality of low frequency RF signals.

10. The method of claim 8 , further comprising:
processing, by an inductor of one of the plurality of output paths, one of the plurality of combined signals to output a processed signal, wherein said controlling the plurality of amounts of current includes modifying an amount of current of the processed signal to output one of the plurality of combined signals.

11. The method of claim 8 , wherein said receiving the high frequency modified RF signal includes:
receiving the high frequency modified RF signal at a high frequency input; and
splitting, at the high frequency input, the high frequency modified RF signal into a plurality of input signals.

12. The method of claim 11 , further comprising:
processing, by a plurality of capacitors of one of the plurality of high frequency paths, one of the plurality of input signals to output one of the plurality of high frequency RF signals.

13. The method of claim 8 , wherein said combining the plurality of low frequency RF signals and the plurality of high frequency RF signals to output the plurality of combined signals to the plurality of plasma processing stations comprises:
combining a first one of the plurality of low frequency RF signals with a first one of the plurality of high frequency RF signals to output a first one of the plurality of combined signals to a first one of the plurality of plasma processing stations;
combining a second one of the plurality of low frequency RF signals with a second one of the plurality of high frequency RF signals to output a second one of the plurality of combined signals to a second one of the plurality of plasma processing stations.

14. The method of claim 8 , wherein the plurality of shunt inductors include a first shunt inductor and a second shunt inductor, wherein the plurality of amounts of current include a first amount of current and a second amount of current, wherein the plurality of plasma processing stations include a first plasma processing station and a second plasma processing station, wherein the plurality of combined signals include a first combined signal and a second combined signal, wherein said controlling, by the plurality of shunt inductors, the plurality of amounts of current provided to the plurality of plasma processing stations comprises:
modifying a first inductance of the first shunt inductor to change the first amount of current provided to the first plasma processing station; and
modifying a second inductance of the second shunt inductor to change the second amount of cur

Assignees

• Lam Res Corp

Inventors

• Augustyniak Edward
• French David
• Kapoor Sunil
• Sakiyama Yukinori
• Thomas George

Classifications

• H10P72/7621

  characterised by supporting two or more semiconductor substrates · CPC title

• H10P72/0606

  Position monitoring, e.g. misposition detection or presence detection · CPC title

• H10P72/0604

  Process monitoring, e.g. flow or thickness monitoring · CPC title

• H10P72/0468

  comprising a chamber adapted to a particular process · CPC title

• H10P72/0466

  characterised by the construction of the load-lock chamber · CPC title