Method and apparatus for etching target object

An apparatus for etching a processing target object, the apparatus comprising:

• a processing vessel;
• a gas supply unit;
• a plasma source;
• and
• a control unit configured to control the gas supply unit and the plasma source,
• wherein the control unit is further configured to perform processes comprising:
• a) providing the processing target object, having a first region containing a first Si-containing material and a second region containing at least one of a metal, an organic material and a second Si-containing material different from the first Si-containing material, into the processing vessel, the first region and the second region being formed to have a top surface at a substantially same height along a surface of the processing target object;
• b) etching the first region by repeating a sequence comprising:
• b-1) exposing the processing target object with a first plasma in the processing vessel and forming a modified layer within the first region by the first plasma;
• b-2) exposing the processing target object with a second plasma in the processing vessel and removing the modified layer by the second plasma,
• wherein the second plasma is generated from a mixed gas containing a fluorine-containing gas, a hydrogen-containing gas, an oxygen-containing gas and an inert gas.