Etching gas composition, substrate processing apparatus, and pattern forming method using the etching gas composition

A substrate processing apparatus comprising:

• a chamber having a processing space in which substrate processing is performed;
• a gas supply device configured to supply an etching gas composition to the processing space;
• and
• a substrate support device disposed in the processing space and configured to support a substrate,
• wherein the etching gas composition comprises at least two C3 or C4 organic fluorine compounds and tantalum fluoride, and
• the at least two C3 or C4 organic fluorine compounds are isomers.

A pattern forming method comprising:

• forming a layer to be etched on a substrate;
• forming an etching mask on the layer to be etched;
• etching the layer to be etched through the etching mask by using plasma obtained from an etching gas composition;
• and
• removing the etching mask,
• wherein the etching gas composition comprises at least two C3 or C4 organic fluorine compounds and tantalum fluoride, and
• the at least two C3 or C4 organic fluorine compounds are isomers.