US 12,444,572 B2
Plasma processing apparatus
Isao Mori, Tokyo (JP); Masaru Izawa, Tokyo (JP); Naoki Yasui, Tokyo (JP); Norihiko Ikeda, Tokyo (JP); and Kazuya Yamada, Tokyo (JP)
Assigned to Hitachi High-Tech Corporation, Tokyo (JP)
Filed by HITACHI HIGH-TECH CORPORATION, Tokyo (JP)
Filed on Apr. 3, 2024, as Appl. No. 18/625,592.
Application 17/861,515 is a division of application No. 16/959,099, granted, now 11,424,105, issued on Aug. 23, 2022, previously published as PCT/JP2019/030660, filed on Aug. 5, 2019.
Application 18/625,592 is a continuation of application No. 17/861,515, filed on Jul. 11, 2022, granted, now 11,978,612.
Prior Publication US 2024/0331974 A1, Oct. 3, 2024
This patent is subject to a terminal disclaimer.
Int. Cl. H01J 37/32 (2006.01); H01L 21/3065 (2006.01); H05H 1/46 (2006.01)
CPC H01J 37/32128 (2013.01) [H01J 37/32183 (2013.01); H01J 37/32577 (2013.01); H01L 21/3065 (2013.01); H05H 1/46 (2013.01); H01J 2237/334 (2013.01)] 7 Claims
OG exemplary drawing
 
1. A plasma processing apparatus, comprising:
a processing chamber in which a sample is subjected to plasma processing:
a first radio frequency power supply that supplies radio frequency power for generating plasma;
a sample stage that includes an electrode to which a first DC voltage for electrostatically attracting the sample is applied, and on which the sample is mounted; and
a second radio frequency power supply that supplies radio frequency power to a substrate of a conductor of the sample stage, wherein
the plasma processing apparatus further comprises a DC power supply that applies a second DC voltage, that is changed according to a periodically repeated waveform, to the substrate different from the electrode,
the waveform of one cycle has a period in which amplitude changes by a predetermined amount or more during a predetermined time,
a ratio of a time during which the second DC voltage rises to a time during which the second DC voltage falls is a value obtained by dividing a value D by a value obtained by subtracting the value D from 1, and
the value D is a value obtained by dividing mobility of ions by a sum of mobility of electrons in a dielectric on the sample and the mobility of the ions in the dielectric.