US 12,176,183 B2
RF voltage and current (V-I) sensors and measurement methods
Barton Lane, Austin, TX (US); Merritt Funk, Austin, TX (US); Yohei Yamazawa, Tokyo (JP); Justin Moses, Austin, TX (US); Chelsea DuBose, Austin, TX (US); and Michael Hummel, Austin, TX (US)
Assigned to Tokyo Electron Limited, Tokyo (JP)
Filed by Tokyo Electron Limited, Tokyo (JP)
Filed on Oct. 13, 2023, as Appl. No. 18/486,220.
Application 18/486,220 is a division of application No. 16/913,545, filed on Jun. 26, 2020, granted, now 11,817,296.
Prior Publication US 2024/0038496 A1, Feb. 1, 2024
Int. Cl. H01J 37/32 (2006.01); G01R 29/08 (2006.01)
CPC H01J 37/32174 (2013.01) [G01R 29/0878 (2013.01)] 18 Claims
OG exemplary drawing
 
1. A radio frequency (RF) sensor assembly comprising:
a sensor casing disposed symmetrically around a central hole, the sensor casing comprising a first conductive cover and a second conductive cover;
a cavity shaped like an annulus disposed symmetrically around the central hole and comprising a first dielectric material, the cavity being bounded by first and second major outer surfaces along a radial direction from a center of the central hole, the first major outer surface comprising a ring-shaped continuous region in physical contact with the central hole, and the second major outer surface comprising a closed outer boundary at a radial distance greater than a radius of the first major outer surface;
a current sensor comprising a current pickup coil disposed symmetrically around the central hole, the current pickup being insulated from the sensor casing and the current pickup being disposed within the cavity; and
a conductive ridge shaped like a ring interposed between the current pickup and the central hole and electrically coupled to the second conductive cover, the conductive ridge being covered with the dielectric material.
 
5. A radio frequency (RF) sensor assembly comprising:
a sensor casing comprising a first conductive cover, a second conductive cover, and a central hole extending through the first and the second conductive covers;
a cavity shaped like an annulus disposed symmetrically around the central hole and comprising an inner groove and an outer groove, the inner and outer grooves comprising a dielectric material;
a current sensor comprising a mandrel and a current pickup disposed within the mandrel, the current sensor being disposed within the cavity between the inner and outer grooves, the current pickup being insulated from the sensor casing by the outer groove; and
a conductive ridge shaped like a ring interposed between the current pickup and the central hole and electrically coupled to the second conductive cover, the conductive ridge being covered with the dielectric material.
 
13. A plasma system comprising:
a process chamber comprising an electrode;
a radio frequency (RF) power source configured to power the process chamber with a RF signal;
a RF pipe coupling the RF power source to the electrode of the process chamber;
a mandrel shaped like a toroid disposed symmetrically around an axis of the RF pipe carrying the RF signal; and
a voltage pickup disposed symmetrically around the axis of the RF pipe and surrounded by the mandrel.