Plasma etching method and plasma etching apparatus

A plasma etching apparatus, comprising:

• a chamber in which a substrate to be subjected to etching is disposed;
• an electrode disposed in the chamber;
• a first process gas introduction unit comprising:
• a raw material tank accommodating a liquid raw material which includes at least one selected from the group consisting of a first fluorocarbon which has a first main chain of six or more carbons bonded in a linear manner, the first main chain having a structure of single bond and double bond alternately joined, a second fluorocarbon which has a second main chain of six or more carbons bonded in a linear manner, the second main chain having a structure of single bond and triple bond alternately joined, and a third fluorocarbon which has a third main chain of five or more carbons bonded in a linear manner, the third main chain having a structure which includes double bond and triple bond;
• and a vaporization mechanism vaporizing the liquid raw material so as to introduce a fluorocarbon gas which includes a vaporized component of the liquid raw material into the chamber;
• and
• a power supply applying a voltage to generate plasma of the fluorocarbon gas to the electrode.