SELECTIVE BARIUM TITANATE ETCHANT Russian patent published in 2018 - IPC H01L21/461 

FIELD: chemistry.

SUBSTANCE: invention relates to compositions for liquid etching ferroelectric films, in particular a film of barium titanate, over a film of platinum on a silicon substrate. Selective etchant of ferroelectric barium titanate includes hydrofluoric acid (10–50 vol.%), sulfuric acid (25–50 vol.%), hydrochloric acid (10–35 vol.%), fluorine-containing surfactant (0.01–0.5 vol.%), deionized water (the rest).

EFFECT: ensuring reproducibility of the topology of the elements of an integrated microcircuit when selectively etching a layer of ferroelectric films of barium titanate on a silicon substrate over SiO₂, PolySi, TiO₂, Pt films and photoresist film mask with a speed not lower than 0,6 microns/min at temperatures not higher than 60 °C.

1 cl, 1 tbl