Method and apparatus for pulse gas delivery with concentration measurement

Patent metadata

Field	Value
Publication number	US-11513108-B2
Application number	US-202016742172-A
Country	US
Kind code	B2
Filing date	Jan 14, 2020
Priority date	Jan 14, 2020
Publication date	Nov 29, 2022
Grant date	Nov 29, 2022

Abstract

A system and method provides a more precise mole delivery amount of a process gas, for each pulse of a pulse gas delivery, by measuring a concentration of the process gas and controlling the amount of gas mixture delivered in a pulse of gas flow based on the received concentration of the process gas. The control of mole delivery amount for each pulse can be achieved by adjusting flow setpoint, pulse duration, or both.

First claim

What is claimed is:

1. A pulse gas control system, the system comprising:
a gas concentration measurement system configured to measure a concentration of a process gas in a gas mixture; and
a pulse gas delivery system including a sensor to sense flow of the gas mixture and a control valve to regulate flow of the gas mixture to a flow setpoint during a pulse duration period, the pulse gas delivery system receiving the measured concentration of the process gas in the gas mixture, measured by the gas concentration measurement system, and adjusting the flow setpoint, during the pulse duration period, based on a changed measured concentration during the pulse duration period to control an amount of gas mixture delivered in a pulse of gas flow, based on the measured concentration of the process gas, to control a mole amount of the process gas delivered to a process chamber during the pulse duration period;
the pulse gas delivery system maintaining a constant pulse duration while adjusting the flow setpoint over time during the pulse duration period until the pulse duration period is complete and a total process gas mole delivery per pulse setpoint is reached, the adjusting comprising adjusting the flow setpoint over time during the pulse duration period based on the remaining time within the pulse and the remaining mole amount of process gas to be delivered within the pulse out of the total process gas mole delivery per pulse setpoint.

2. The system of claim 1 , wherein the pulse gas delivery system sets an initial target flow setpoint of the gas mixture in inverse proportion to the received concentration of the process gas.

3. The system of claim 1 , wherein the gas concentration measurement system comprises an optical gas sensor, a surface acoustic wave device, an ultrasound sensor, a mass spectrometer or a thermal conductive detector.

4. The system of claim 1 , wherein the gas concentration measurement system is arranged in series between a source of the gas mixture and the pulse gas delivery system, to receive the gas mixture from a source and to provide the gas mixture to the pulse gas delivery system.

5. The system of claim 1 , wherein the gas concentration measurement system is arranged to receive a sample of the gas mixture from a sample line that samples a gas flow of the gas mixture from a source to the pulse gas delivery system.

6. The system of claim 1 , wherein the process chamber to which the pulse gas delivery system is configured to deliver the process gas is one of: an Atomic Layer Deposition (ALD) process, an Atomic Layer Etch (ALE) process, a Through Silicon Via (TSV) process, a pulsed deep reactive ion etch (DRIE) process, a plasma enhanced chemical vapor deposition (CVD) process and a plasma enhanced etching process.

7. A method of controlling a pulse gas delivery system, the method comprising:
measuring a concentration of a process gas in a gas mixture using a gas concentration measurement system;
with the pulse gas delivery system, receiving the measured concentration of the process gas in the gas mixture, the pulse gas delivery system including a sensor to sense flow of the gas mixture and a control valve to regulate flow of the gas mixture to a flow setpoint during a pulse duration period;
adjusting the flow setpoint, during the pulse duration period, based on a changed measured concentration during the pulse duration period to control an amount of gas mixture delivered in a pulse of gas flow by the pulse gas delivery system, based on the measured concentration of the process gas, to control a mole amount of the process gas delivered to a process chamber during the pulse duration period; and
maintaining a constant pulse duration while adjusting the flow setpoint over time during the pulse duration period until the pulse duration period is complete and a total process gas mole delivery per pulse setpoint is reached, the adjusting comprising adjusting the flow setpoint over time during the pulse duration period based on the remaining time within the pulse and the remaining mole amount of process gas to be delivered within the pulse out of the total process gas mole delivery per pulse setpoint.

8. The method of claim 7 , comprising setting an initial target flow setpoint of the gas mixture in inverse proportion to the received concentration of the process gas.

9. The method of claim 7 , comprising measuring the concentration of the process gas in the gas mixture using an optical gas sensor, a surface acoustic wave device, an ultrasound sensor, a mass spectrometer or a thermal conductive detector.

10. The method of claim 7 , comprising using the pulse gas delivery system to deliver the process gas to one of: an Atomic Layer Deposition (ALD) process, an Atomic Layer Etch (ALE) process, a Through Silicon Via (TSV) process, a pulsed deep reactive ion etch (DRIE) process, a plasma enhanced chemical vapor deposition (CVD) process and a plasma enhanced etching process.

11. A pulse gas control system, the system comprising:
a gas concentration measurement system configured to measure a concentration of a process gas in a gas mixture; and
a pulse gas delivery system configured to sense flow of the gas mixture and control flow of the gas mixture and to receive the concentration of the process gas in the gas mixture, measured by the gas concentration measurement system, and to control an amount of gas mixture delivered in a pulse of gas flow, based on the received concentration of the process gas, to control a mole amount of the process gas delivered to a process chamber in the pulse;
wherein the pulse gas delivery system is configured to adjust a flow setpoint of the gas mixture during the pulse based on the received concentration of the process gas, and the pulse gas delivery system sets an initial target flow setpoint of the gas mixture in inverse proportion to the received concentration of the process gas; and
wherein the pulse gas delivery system sets the initial target flow setpoint in proportion to a process gas mole delivery per pulse setpoint divided by a product of a pulse duration period multiplied by the received concentration of the process gas.

12. A pulse gas control system, the system comprising:
a gas concentration measurement system configured to measure a concentration of a process gas in a gas mixture; and
a pulse gas delivery system configured to sense flow of the gas mixture and control flow of the gas mixture and to receive the concentration of the process gas in the gas mixture, measured by the gas concentration measurement system, and to control an amount of gas mixture delivered in a pulse of gas flow, based on the received concentration of the process gas, to control a mole amount of the process gas delivered to a process chamber in the pulse;
wherein the pulse gas delivery system is configured to adjust a flow setpoint of the gas mixture during the pulse; and
wherein the pulse gas delivery system adjusts the flow setpoint, during a pulse duration period, based on a changed measurement of the process gas concentration during the pulse duration period, based on a relationship:

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Assignees

• Mks Instr Inc

Inventors

• Ye Jim
• Saptari Vidi
• Ding Junhua

Classifications

• H10P72/0604

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

• C23C16/45544

  characterized by the apparatus · CPC title

• C23C16/52 Primary

  Controlling or regulating the coating process {(C23C16/45557, C23C16/279 take precedence)} · CPC title

• G05D7/0694

  by action on throttling means or flow sources of very small size, e.g. microfluidics (microvalves F16K99/0001; microstructural devices per se B81B) · CPC title

• G05D21/02 Primary

  characterised by the use of electric means · CPC title