Method for forming pattern of metal oxide and method for producing semiconductor element

A method for forming a pattern of metal oxide by etching the metal oxide using an etching gas,

• the metal oxide containing oxide of at least one of tin and indium, the method comprising:
• a preparation step of preparing a member to be etched including a base, a metal oxide layer containing the metal oxide and laminated directly or via an underlying layer on the base, and a template layer containing a carbon-containing material and laminated on the metal oxide layer and in which the metal oxide layer is an etching object which is an object to be etched by the etching gas, and the base, the underlying layer, and the template layer are non-etching objects which are not the objects to be etched by the etching gas;
• a template manufacturing step of forming a predetermined pattern on the template layer of the member to be etched;
• and
• an etching step of bringing a gas containing halon having a fluorine atom, a bromine atom, and a carbon atom in a molecule, in which a number of the carbon atoms is 1 or more and 3 or less, as the etching gas into contact with the member to be etched in which the predetermined pattern is formed on the template layer in the template manufacturing step, in a presence of plasma, performing etching while a bias power is being applied to a lower electrode supporting the member to be etched and selectively etching the metal oxide layer relative to the base, the template layer, and the underlying layer, and transferring the predetermined pattern of the template layer to the metal oxide layer,
• wherein the halon is at least one of bromofluoromethane, bromofluoroethylene, and bromofluoropropene,
• wherein the bromofluoromethane is dibromodifluoromethane,
• wherein the bromofluoroethylene is at least one of bromotrifluoroethylene, 1-bromo-2,2-difluoroethylene, (E)-1-bromo-1,2-difluoroethylene, (Z)-1-bromo-1,2-difluoroethylene, 1-bromo-1-fluoroethylene, (E)-1-bromo-2-fluoroethylene, (Z)-1-bromo-2-fluoroethylene, 1,1-dibromo-2-fluoroethylene, (E)-1,2-dibromo-2-fluoroethylene, (Z)-1,2-dibromo-2-fluoroethylene, and tribromofluoroethylene, and
• wherein the bromofluoropropene is at least one of (E)-1-bromo-3,3,3-trifluoromethylpropene, (Z)-1-bromo-3,3,3-trifluoromethylpropene, and 2-bromo-3,3,3-trifluoromethylpropene.