Patent ID: 10199564

Abstract:
This method for manufacturing a lead-free niobate-system ferroelectric thin film device includes: a lower electrode film formation step of forming a lower electrode film on a substrate; a ferroelectric thin film formation step of forming a niobate-system ferroelectric thin film on the lower electrode film; an etch mask pattern formation step of forming an etch mask in a desired pattern on the niobate-system ferroelectric thin film; and a ferroelectric thin film etching step of shaping the niobate-system ferroelectric thin film into a desired fine pattern by wet etching using an etchant comprising: a predetermined chelating agent including at least one selected from EDTMP, NTMP, CyDTA, HEDP, GBMP, DTPMP, and citric acid; an aqueous alkaline solution containing an aqueous ammonia solution; and an aqueous hydrogen peroxide solution.