US 12,255,049 B2
Plasma processing apparatus and plasma processing method
Koichi Nagami, Miyagi (JP); Kazuya Nagaseki, Miyagi (JP); and Shinji Himori, Miyagi (JP)
Assigned to TOKYO ELECTRON LIMITED, Tokyo (JP)
Filed by TOKYO ELECTRON LIMITED, Tokyo (JP)
Filed on Nov. 5, 2019, as Appl. No. 16/674,506.
Claims priority of application No. 2018-208007 (JP), filed on Nov. 5, 2018.
Prior Publication US 2020/0144028 A1, May 7, 2020
Int. Cl. H01L 21/00 (2006.01); H01J 37/32 (2006.01)
CPC H01J 37/32027 (2013.01) [H01J 37/32082 (2013.01); H01J 37/32266 (2013.01); H01J 37/32577 (2013.01)] 22 Claims
OG exemplary drawing
 
1. A plasma processing apparatus, comprising:
a chamber;
a gas source which supplies an etching gas into the chamber;
a substrate support which supports a substrate;
an electrostatic chuck;
a direct current (DC) power supply which supplies a DC voltage to the electrostatic chuck to attract the substrate;
a source radio-frequency (RF) power supply to supply an RF power;
a bias power supply for bias that is electrically connected to the substrate support, the bias power supply applying voltage pulses to attract ions; and
a processor configured to execute a control program to control the bias power supply to:
(a) stop an application of any non-zero voltage pulse from the bias power supply to the substrate support in a first time period during which an etching plasma is generated from the etching gas in the chamber;
after (a), (b) apply a first voltage pulse, which is a positive voltage pulse, to the substrate support in a second time period during which the etching plasma is generated from the etching gas in the chamber, the second time period being after the first time period and the second time period being shorter than the first time period;
after (b), (c) apply a second voltage pulse, which is a negative voltage pulse, to the substrate support to etch the substrate in a third time period during which the etching plasma is generated from the etching gas in the chamber, the third time period being after the second time period and the third time period being longer than the second time period; and
repeatedly perform (a)-(c) until a condition is satisfied, wherein an application of the first voltage pulse in the second time period is directly switched to an application of the second voltage pulse in the third time period.