US 11,868,147 B2
Optical emission spectroscopy control of gas flow in processing chambers
Philip DiGiacomo, Palo Alto, CA (US); Sunil Kumar Garg, Santa Clara, CA (US); Paul G. Kiely, Santa Cruz, CA (US); Keith A. Miller, Sunnyvale, CA (US); and Rajat Agrawal, Bangalore (IN)
Assigned to Applied Materials, Inc., Santa Clara, CA (US)
Filed by Applied Materials, Inc., Santa Clara, CA (US)
Filed on Mar. 11, 2021, as Appl. No. 17/198,619.
Prior Publication US 2022/0291702 A1, Sep. 15, 2022
Int. Cl. G05D 11/13 (2006.01); G05B 15/02 (2006.01); G01N 21/67 (2006.01)
CPC G05D 11/138 (2013.01) [G01N 21/67 (2013.01); G05B 15/02 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A method of controlling gas levels in chambers using optical measurements, the method comprising:
capturing a baseline set of measurements indicative of an amount of a gas species in a Physical Vapor Deposition (PVD) chamber over time as a magnet oscillates in the PVD chamber to position a plasma in the PVD chamber;
receiving, from an Optical Emission Spectrometer (OES), a measurement that is indicative of an amount of the gas species in the PVD chamber while performing a current process on a semiconductor substrate in the PVD chamber;
using the baseline set of measurements to normalize the measurement that is indicative of the amount of the gas species in the PVD chamber to minimize an effect of the magnet;
providing the measurement as a feedback input to a control process that is configured to maintain a predetermined target amount of the gas species in the PVD chamber;
generating a setpoint from the control process for a gas flow controller that controls an amount of the gas species that flows into the PVD chamber while performing the current process on the semiconductor substrate; and
causing the gas flow controller to provide the gas species to the PVD chamber using the setpoint from the control process.