US 12,272,520 B2
Process control enabled VDC sensor for plasma process
Merritt Funk, Austin, TX (US); Peter Ventzek, Austin, TX (US); Alok Ranjan, Austin, TX (US); Barton Lane, Austin, TX (US); Justin Moses, Austin, TX (US); and Chelsea DuBose, Austin, TX (US)
Assigned to Tokyo Electron Limited, Tokyo (JP)
Filed by Tokyo Electron Limited, Tokyo (JP)
Filed on Jul. 9, 2019, as Appl. No. 16/506,202.
Prior Publication US 2021/0013005 A1, Jan. 14, 2021
Int. Cl. H01J 37/32 (2006.01); C23C 16/509 (2006.01); H01L 21/67 (2006.01); H01L 21/683 (2006.01)
CPC H01J 37/32091 (2013.01) [C23C 16/509 (2013.01); H01J 37/32174 (2013.01); H01J 37/3244 (2013.01); H01J 37/32559 (2013.01); H01L 21/67109 (2013.01); H01L 21/6831 (2013.01)] 23 Claims
OG exemplary drawing
 
1. A plasma processing system configured to process a substrate, comprising:
a plasma chamber comprising a substrate holder and a focus ring;
a radio frequency (RF) source configured to apply an RF field to the plasma chamber to generate an RF plasma in the plasma chamber;
an electric displacement field measurement sensor comprising a capacitive dielectric layer attached to the focus ring, the capacitive dielectric layer being a ferroelectric material, the electric displacement field measurement sensor being configured to detect a change in polarization of the ferroelectric material during substrate processing, the electric displacement field measurement sensor comprising a sensing capacitor embedded within the capacitive dielectric layer attached to the focus ring, the sensing capacitor comprising two capacitor pickup plates disposed in the capacitive dielectric layer and configured to produce a differential capacitance signal; and
control electronics coupled to the electric displacement field measurement sensor, the control electronics being configured to determine a direct current (DC) voltage (Vdc) of the RF plasma during a plasma process based on the change in the polarization, wherein the Vdc is the voltage between the substrate and a plasma sheath of the RF plasma.