Method of producing etching mask, etching mask precursor, and oxide layer, and method of manufacturing thin film transistor

A method of producing an oxide layer, the method comprising

• an etching-mask forming step of forming a pattern of an etching mask including aliphatic polycarbonate on the oxide layer by the screen printing method,
• a contact step of, after the etching-mask forming step, contacting the oxide layer with a solution for dissolving a portion of the oxide layer not protected by the etching mask, and
• a heating step of, after the contact step, heating the oxide layer and the etching mask to or above a temperature at which the etching mask is decomposed.

A method of producing an oxide layer, the method comprising

• an etching-mask forming step of forming a pattern of an etching mask including aliphatic polycarbonate on an oxide precursor layer to be oxidized into the oxide layer by the screen printing method,
• a contact step of, after the etching-mask forming step, contacting the oxide precursor layer with a solution for dissolving a portion of the oxide precursor layer not protected by the etching mask, and
• a heating step of, after the contact step, heating the oxide precursor layer and the etching mask to or above a temperature at which the oxide layer is formed.

A method of producing an oxide layer, the method comprising

• an etching-mask forming step of forming a pattern of an etching mask including aliphatic polycarbonate on the oxide layer by the screen printing method,
• an exposure step of, after the etching-mask forming step, exposing the oxide layer to a plasma for etching a portion of the oxide layer not protected by the etching mask, and
• a heating step of, after the exposure step, heating the oxide layer and the etching mask to or above a temperature at which the etching mask is decomposed.

A method of producing an oxide layer, the method comprising

• an etching-mask forming step of forming a pattern of an etching mask including aliphatic polycarbonate on an oxide precursor layer to be oxidized into the oxide layer by the screen printing method,
• an exposure step of, after the etching-mask forming step, exposing the oxide precursor layer to a plasma for etching a portion of the oxide precursor layer not protected by the etching mask, and
• a heating step of, after the exposure step, heating the oxide precursor layer and the etching mask to or above a temperature at which the oxide layer is formed.

(canceled)