Abstract: An etching method includes: (a) providing, on a support, a substrate having the first region covering the second region and the second region defining a recess receiving the first region, (b) etching the first region until or immediately before the second region is exposed, (c) exposing the substrate to plasma generated from a first process gas containing C and F atoms using a first RF signal and forming a deposit on the substrate, (d) exposing the deposit to plasma generated from a second process gas containing an inert gas using a first RF signal and selectively etching the first region to the second region, and (e) repeating (c) and (d). (c) includes using the RF signal with a frequency of 60 to 300 MHz and/or setting the support to 100 to 200° C. to control a ratio of C to F atoms in the deposit to greater than 1.

Abstract: There is provided a radio frequency power filter circuit used in a plasma processing apparatus that includes an electrode and a feeding body connected to a center of a rear surface of the electrode and generates plasma by applying radio frequency power, the filter circuit including a series resonance circuit provided in a wiring line between a conductive member provided in the plasma processing apparatus and a power supply configured to supply DC power or power having a frequency of less than 400 kHz to the conductive member, and including a coil connected in series to the wiring line and a capacitor connected between the wiring line and a ground. A central axis of the coil and a central axis of the feeding body coincide with each other.

Abstract: An etching method includes: (a) providing, on a support, a substrate having the first region covering the second region and the second region defining a recess receiving the first region, (b) etching the first region until or immediately before the second region is exposed, (c) exposing the substrate to plasma generated from a first process gas containing C and F atoms using a first RF signal and forming a deposit on the substrate, (d) exposing the deposit to plasma generated from a second process gas containing an inert gas using a first RF signal and selectively etching the first region to the second region, and (e) repeating (c) and (d). (c) includes using the RF signal with a frequency of 60 to 300 MHz and/or setting the support to 100 to 200° C. to control a ratio of C to F atoms in the deposit to greater than 1.