High voltage resistive output stage circuit

Patent metadata

Field	Value
Publication number	US-2021066042-A1
Application number	US-202017098207-A
Country	US
Kind code	A1
Filing date	Nov 13, 2020
Priority date	Feb 28, 2014
Publication date	Mar 4, 2021
Grant date	—

Abstract

Some embodiments include a high voltage, high frequency switching circuit. The switching circuit may include a high voltage switching power supply that produces pulses having a voltage greater than 1 kV and with frequencies greater than 10 kHz and an output. The switching circuit may also include a resistive output stage electrically coupled in parallel with the output and between the output stage and the high voltage switching power supply, the resistive output stage comprising at least one resistor that discharges a load coupled with the output. In some embodiments, the resistive output stage may be configured to discharge over about 1 kilowatt of average power during each pulse cycle. In some embodiments, the output can produce a high voltage pulse having a voltage greater than 1 kV and with frequencies greater than 10 kHz with a pulse fall time less than about 400 ns.

First claim

That which is claimed:

1 . A method of processing of a substrate, comprising:
generating a plasma within a plasma chamber; and biasing the plasma with a bias generator that is electrically coupled to the plasma chamber, the bias generator establishes a pulsed voltage waveform, and the pulsed voltage waveform comprises a series of repeating cycles, wherein a waveform within each cycle of the series of repeating cycles has a first portion that occurs during a first time interval and a second portion that occurs during a second time interval, wherein a voltage pulse is only present during the first time interval, wherein the bias generator comprises:
a pulse generator that is electrically coupled to the plasma chamber; and
a current-return output stage, wherein a first end of the current-return output stage is electrically coupled with the plasma chamber and the pulse generator, and a second end of the current-return output stage is electrically coupled to the ground, wherein a current flows from the plasma chamber to ground through the current-return output stage during at least a portion of the second time interval.

2 . The method of claim 1 , wherein the first portion of the waveform further comprises a positive voltage pulse resulting in restoration of a sheath voltage drop, wherein a sheath is formed over a plasma facing surface of the substrate at the end of the first time interval.

3 . The method of claim 1 , wherein the first time interval has a time duration of between about 200 ns and about 400 ns.

4 . The method of claim 1 , wherein the cycle of the series of repeating cycles has a time duration of between about 2 microseconds and about 3 microseconds.

5 . The method of claim 1 , wherein the voltage pulse is between about 0.1 kilovolts and about 10 kilovolts.

6 . The method of claim 1 , further comprising: applying a DC voltage to the plasma chamber using a chucking power supply that is electrically coupled to the bias generator.

7 . A processing chamber, comprising:
a plasma chamber; and a bias generator that is electrically coupled to the plasma chamber, wherein the bias generator comprises:
a pulse generator; and
a current-return output stage, wherein a first end of the current-return output stage is electrically coupled to the pulse generator and the plasma chamber.

8 . The processing chamber of claim 7 , further comprising: an inductively coupled plasma source or a capacitively coupled plasma source that is configured to generate a plasma within the plasma chamber.

9 . The processing chamber of claim 7 , further comprising: a DC bias power supply that is electrically coupled to the plasma chamber.

10 . A processing chamber, comprising:
a substrate support assembly comprising a biasing electrode that is separated from a substrate supporting surface of the substrate support assembly by a layer of a dielectric material; and a bias generator that is electrically coupled to a generator end of an electrical conductor using a generator coupling assembly, and an electrode end of the electrical conductor is electrically coupled to the biasing electrode using an electrode coupling assembly, wherein the bias generator comprises:
a pulse generator that is electrically coupled to the generator end of the electrical conductor; and
a current-return output stage, wherein a first end of the current-return output stage is electrically coupled to the electrical conductor, and a second end of the current-return output stage is electrically coupled to the ground.

11 . The processing chamber of claim 10 , wherein the positive voltage pulse results in restoration of a sheath voltage drop formed over a plasma facing surface of the substrate at the end of the first time interval, and a current flows from the biasing electrode to ground through the current-return output stage during at least a portion of the second time interval.

12 . The processing chamber of claim 10 , wherein first time interval has a duration of between about 200 ns and about 400 ns.

13 . The processing chamber of claim 10 , wherein the first time interval is less than about 20% of a time duration of a cycle of the series of repeating cycles.

14 . The processing chamber of claim 10 , wherein the cycle of the series of repeating cycles has a period that has a duration of between about 2 μs and about 3 μs.

15 . The processing chamber of claim 10 , wherein a first end of the pulse generator is electrically coupled to the generator end of the electrical conductor, and a second end of the pulse generator is electrically coupled to ground.

16 . The processing chamber of claim 10 , wherein the generator coupling assembly comprises one of the components selected from the group consisting of a capacitor, a capacitor and an electrical conductor in series, an inductor, and an inductor and an electrical conductor in series.

17 . A processing chamber, comprising:
a pulsed DC biasing system, comprising:
a plasma chamber for producing a plasma for semiconductor processing;
a bias generator electrically coupled with the plasma chamber that establishes a pulsed voltage waveform, the bias generator comprising:
a pulse generator; and
a current-return output stage, wherein a first end of the current-return output stage is electrically coupled with the pulse generator, and a second end of the current-return output stage is electrically coupled to ground; and

a blocking capacitor disposed between the bias generator and the plasma chamber.

18 . The processing chamber of claim 17 , wherein the plasma chamber includes layer of dielectric material.

19 . The processing chamber of claim 17 , wherein a high-voltage DC supply is electrically coupled with the plasma chamber at a connection point disposed between the plasma chamber and the blocking capacitor.

20 . The processing chamber of claim 17 , further comprising a resistor disposed between the high-voltage DC supply and the connection point.

21 . The processing chamber of claim 17 , further comprising a high-voltage DC supply electrically coupled between ground and the plasma chamber, wherein the high-voltage DC supply applies a voltage to the plasma chamber relative to the ground.

22 . A method of processing a substrate, comprising:
generating a plasma within a plasma chamber; establishing a pulsed voltage waveform at the biasing electrode using a bias generator that is electrically coupled with the plasma chamber through a blocking capacitor and one or more electrical conductors; and delivering a chucking voltage from a high-voltage power supply to the plasma chamber through one of the one or more electrical conductors, wherein the blocking capacitor is disposed between the high-voltage module and the bias generator.

23 . The method of claim 22 , wherein the pulsed voltage waveform comprises a series of repeating cycles, a waveform within each cycle of the series of repeating cycles has a first portion that occurs during a first time interval and a second portion that occurs during a second time interval, and a positive voltage pulse is only present during the first time interval.

24 . The method of claim 22 , wherein the bias generator comprises: a current-return output stage, wherein a first end of the current-return output stage is electrically coupled with the pulse generator and the plasma chamber.

25 . The method of claim 22 , wherein a current flow

Assignees

• Eagle Harbor Tech Inc

Inventors

• Ziemba Timothy M
• Miller Kenneth E
• Prager James R
• Carscadden John G
• Slobodov Ilia

Classifications

• H01J2237/2485

  Electric or electronic means · CPC title

• H01J37/32091

  the radio frequency energy being capacitively coupled to the plasma · CPC title

• H03K3/53

  by the use of an energy-accumulating element discharged through the load by a switching device controlled by an external signal and not incorporating positive feedback (H03K3/335 takes precedence) · CPC title

• H01J37/32348

  Dielectric barrier discharge · CPC title

• H01J37/32174 Primary

  Circuits specially adapted for controlling the RF discharge · CPC title