ETCHANT AND ETCHING METHOD FOR OXIDE COMPRISING INDIUM, GALLIUM AND OXYGEN, OR INDIUM, GALLIUM, ZINC AND OXYGEN

摘要

PROBLEM TO BE SOLVED: To provide an etchant having a suitable etching rate, causing no generation of deposits, good in removability of residues, low in corrosiveness against a wiring material, small in change of an etching rate to the dissolution of an oxide, and further long in life of an etchant, in etching an oxide comprising indium, gallium and oxygen, or indium, gallium, zinc and oxygen.SOLUTION: In etching an oxide comprising indium, gallium and oxygen, or indium, gallium, zinc and oxygen, a suitable etching rate is achieved, removability of residues is also good, corrosiveness against a wiring material is also low, further deposits are not generated even when the concentration of an oxide dissolved in an etchant becomes a high concentration, and a suitable etching rate can be maintained, by using an etchant including a sulfuric acid or a salt thereof, and a carboxylic acid (excluding an oxalic acid) or a salt thereof.