METHOD OF ETCHING HAFNIUM OXIDE

摘要

PROBLEM TO BE SOLVED: To provide a method of etching hafnium oxide by which the hafnium oxide formed on a substrate can be etched satisfactorily. SOLUTION: In the method of etching hafnium oxide, an etchant composed of a mixed solution of a hydrofluoric acid and a concentrated sulfuric acid is supplied to a substrate W held by a spin chuck 1 from an etchant supplying nozzle 11 (an etching step with hydrofluoric acid). Then the etchant is washed away from the surface of the substrate W by supplying a pre-rinsing solution composed of a concentrated sulfuric acid or concentrated acetic acid to the substrate W from a pre-rinsing solution supply nozzle 12 (pre-rinsing step). Thereafter, the pre-rinsing solution is washed away from the substrate W by supplying pure water to the substrate W from a pure water supply nozzle 13 (rinsing step with pure water). Since the hydrofluoric acid is washed away from the substrate W in a state where no water exists on the substrate W and thereafter the rinsing is performed with the pure water, the constituent material of the substrate W is not etched undesirably by the hydrofluoric acid. COPYRIGHT: (C)2005,JPO&NCIPI