COMPOSITION FOR SELECTIVE ETCH FOR CHEMICAL PROCESS OF THINNING OF SILICON PLATES Russian patent published in 2017 - IPC H01L21/306 

FIELD: chemistry.

SUBSTANCE: invention relates to compositions of selective polishing etches used in processes of chemical thinning of epitaxial silicon plates in the manufacture of semiconductor devices and integrated circuits. Composition for selective etch for chemical processes of thinning silicon plates includes 1 volume part of hydrofluoric acid, 3 volume parts of nitric acid, N volume parts of acetic acid, where N ranges from 6 to 12 depending on specific requirements to speed and selectivity of the etching process, and 0.5÷1 part of 0.1 % solution of the synthesized fluor derivative ampholytic complex SAA with cation-active and anion-active groups based on surfactants of types R_FSO₂-N-R₁R₂R₃-R₄+A^-, where A represents anion of halogen, and R_FSO₂-N-R₁R₂R₃R₄-K⁺, where K is a cation (sodium, potassium, ammonium), a R_(F) – radical containing fluoride ions, wherein the cation and anion groups of the ampholytic complex are taken in equal portions, and flactonites A76 and K76 are used as surfactants.

EFFECT: technical result consists in achieving high stability of etching process and high quality of polished surface formed by silicon membrane.

3 cl, 3 dwg, 1 tbl