Pulse plasma apparatus and drive method thereof

Patent metadata

Field	Value
Publication number	US-9378931-B2
Application number	US-201514796188-A
Country	US
Kind code	B2
Filing date	Jul 10, 2015
Priority date	Oct 29, 2014
Publication date	Jun 28, 2016
Grant date	Jun 28, 2016

Abstract

A pulse plasma apparatus includes a process chamber, source RF generator configured to supply first and second level RF pulse power having first and second duty cycles to an upper electrode of the process chamber, a reflected power indicator configured to indicate reflection RF power, a first matching network, and a controller. The first matching network is configured to match an impedance of the process chamber with an impedance of the source RF generator as a first or second matching capacitance value, respectively when the first level RF pulse power or second level RF pulse power is supplied, respectively. The controller is configured to calculate a third matching capacitance value based on the first and second matching capacitance values and a ratio of the first and second duty cycles, provide the third matching capacitance values to the first matching network, and control the source RF generator and first matching network.

First claim

What is claimed is:

1. A pulse plasma apparatus comprising:
a process chamber including an upper electrode and a lower electrode;
a source RF generator configured to supply first level RF pulse power and second level RF pulse power, the first level RF pulse power having a first duty cycle to the upper electrode, and the second level RF pulse power having a second duty cycle to the upper electrode;
a reflected power indicator configured to indicate reflection RF power, the reflection RF power being RF power re-reflected from the process chamber to the source RF generator;
a first matching network configured to match a plasma impedance of the process chamber with an impedance of the source RF generator as a first matching capacitance value when the first level RF pulse power is supplied, and match the plasma impedance of the process chamber with the impedance of the source RF generator as a second matching capacitance value when the second level RF pulse power is supplied; and
a controller configured to calculate a third matching capacitance value based on the first matching capacitance value, the second matching capacitance value and a ratio of the first and second duty cycles, provide the third matching capacitance value to the first matching network, and control the source RF generator and the first matching network.

2. The pulse plasma apparatus of claim 1 , wherein the first level RF pulse power has a smaller value than the second level RF pulse power.

3. The pulse plasma apparatus of claim 1 , wherein
the first and second duty cycles are identical to each other, and
the controller is configured to calculate an intermediate value of the first and second matching capacitance values as the third matching capacitance value.

4. The pulse plasma apparatus of claim 1 , further comprising:
a first bias RF generator configured to supply third level RF pulse power to the lower electrode; and
a synchronization device connected to the source RF generator and the first bias RF generator, and configured to synchronize the first duty cycle of the first level RF pulse power with a duty cycle of the third level RF pulse power.

5. The pulse plasma apparatus of claim 4 , wherein the synchronization device is configured to control the first bias RF generator such that the third level RF pulse power is not supplied to the lower electrode while the source RF generator supplies the first level RF pulse power to the upper electrode at the first duty cycle, and
the synchronization device is configured to perform duty cycle synchronization by supplying the third level RF pulse power to the lower electrode at the second duty cycle while the source RF generator supplies the second level RF pulse power to the upper electrode at the second duty cycle.

6. The pulse plasma apparatus of claim 4 , further comprising:
a second bias RF generator configured to be connected to the lower electrode, and supply fourth RF pulse power, the fourth RF pulse power having a lower frequency than the third level RF pulse power to the lower electrode.

7. The pulse plasma apparatus of claim 6 , wherein the source RF generator is configured to supply the first and second level RF pulse powers at a frequency of 100 MHz to 200 MHz,
the first bias RF generator is configured to supply the third level RF pulse power at a frequency of 2 MHz to 100 MHz,
the second bias RF generator is configured to supply fourth level RF power at a frequency of 0 MHz to 2 MHz.

8. The pulse plasma apparatus of claim 1 , wherein the controller comprises:
a memory configured to store the first and second matching capacitance values; and
an arithmetic device configured to perform an algorithm that assigns a weight to the first and the second matching capacitance values according to the ratio of the first and second duty cycles, and calculates the third matching capacitance value that matches the plasma impedance of the process chamber with the impedance of the source RF generator.

9. A drive control method of a pulse plasma apparatus comprising:
supplying first RF power in a continuous wave mode to an upper electrode of a process chamber by a source RF generator during a first time period;
determining a first matching capacitance value so as to match a plasma impedance of the process chamber with an impedance of the source RF generator;
supplying second RF power in the continuous wave mode to the upper electrode by the source RF generator during a second time period;
determining a second matching capacitance value so as to match the plasma impedance of the process chamber with the impedance of the source RF generator;
calculating a third matching capacitance value by a controller based on the first matching capacitance value and the second matching capacitance value;
transmitting the third matching capacitance value to the first matcher by the controller; and
alternately supplying first level RF pulse power having a first duty cycle and second level RF pulse power having a second duty cycle to the upper electrode by the source RF generator.

10. The method of claim 9 , wherein the calculating a third matching capacitance comprises:
calculating a ratio of the first and second duty cycles; and
calculating the third matching capacitance value by applying weights according to the ratio to the first and second matching capacitance values, respectively.

11. The method of claim 9 , further comprising:
storing the first matching capacitance values in a memory; and
storing the second matching capacitance values in the memory.

12. The method of claim 9 , wherein the supplying first RF power by the source RF generator comprises supplying third RF power to a lower electrode of the process chamber during the first time period by a first bias RF generator connected to the lower electrode.

13. The method of claim 12 , wherein the supplying first RF power by the source RF generator comprises supplying fourth RF power to the lower electrode during the first time period by a second bias RF generator connected to the lower electrode.

14. The method of claim 12 , further comprising:
synchronizing the supplying of the first and third RF powers to the upper electrode and the lower electrode at the first and second duty cycles.

15. The method of claim 14 , wherein RF pulse power is not supplied to the lower electrode while the first level RF pulse power having the first duty cycle is supplied to the upper electrode, and
the third level RF pulse power having the second duty cycle is supplied to the lower electrode while the second level RF pulse power having the second duty cycle is supplied to the upper electrode.

16. A pulse plasma apparatus comprising:
a process chamber including an upper electrode and a lower electrode;
a source RF generator configured to supply source RF powers to the upper electrode, the source RF powers including first RF power in a continuous wave form during a first time period, second RF power in a continuous waver form during a second time period, and the first and second level RF pulse powers supplied in an alternating manner during a third time period, the first level RF pulse power having a first duty cycle, the second level RF pulse power having a second duty cycle, the third time period following the second time period, the second time period following the first time period;
a bias RF generator configured to supply bias RF power to the lower electrode, the bias RF power having a third duty cycle;
a reflected power indicator configured to indicate reflection RF power, the reflection RF power being RF power reflected from

Assignees

• Samsung Electronics Co Ltd

Inventors

• Kwon Ohyung
• Kang Namjun
• Sung Doug-Yong
• Cho Jung-Hyun

Classifications

• H01J7/24

  Cooling arrangements; Heating arrangements; Means for circulating gas or vapour within the discharge space · CPC title

• H01J2237/327

  Arrangements for generating the plasma · CPC title

• H01J2237/334

  Etching · CPC title

• H01J37/32183 Primary

  Matching circuits · CPC title

• H05B31/26

  Influencing the shape of arc discharge by gas blowing devices · CPC title