US 12,265,057 B2
Monitoring radical particle concentration using mass spectrometry
Chenglong Yang, Fremont, CA (US); Jimmy Liu, San Jose, CA (US); and James Edward Blessing, Morgan Hill, CA (US)
Assigned to MKS INSTRUMENTS, INC., Andover, MA (US)
Filed by MKS Instruments, Inc., Andover, MA (US)
Filed on Mar. 29, 2024, as Appl. No. 18/621,600.
Application 18/621,600 is a continuation of application No. 17/644,704, filed on Dec. 16, 2021, granted, now 11,971,386.
Claims priority of provisional application 63/130,257, filed on Dec. 23, 2020.
Prior Publication US 2024/0264116 A1, Aug. 8, 2024
Int. Cl. G01N 27/623 (2021.01); H01J 49/28 (2006.01)
CPC G01N 27/623 (2021.01) [H01J 49/282 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A radical particle monitor, comprising:
a tubular flow channel configured to transmit, along an axis thereof, a gas including radicals;
a test chamber coupled to the flow channel so as to be offset from the axis of the flow channel, wherein an interior of the test chamber and an interior of the flow channel are in fluid communication with one another via an aperture located between the interior of the flow channel and the interior of the test chamber;
an ionizer positioned within the interior of the test chamber, wherein the ionizer has a line-of-sight with the aperture; and
a mass analyzer coupled to the test chamber.