Etching composition and method for selectively removing silicon nitride during manufacture of a semiconductor device

A composition comprising:

• A. greater than approximately 70% by weight of neat phosphoric acid;
• and
• B. a mixture comprising at least one of:
• I. a compound of Formula I:
• wherein:
• (i) m=0-20,
• (ii) each of R1, R2, R3, R4 and R5 is independently selected from the group of hydrogen, a C1 to C10 linear alkyl group, a C1 to C10 linear alkyl group substituted with fluorine, a nitrogen-containing group, an oxygen-containing group, a C3 to C10 branched alkyl group, a C3 to C10 cyclic alkyl group, a C5 to C12 aryl group, a C2 to C10 linear or branched alkenyl group and a C2 to C10 linear or branched alkynyl group,
• and
• (iii) each of Ra and Rb is independently selected from a C1 to C10 linear alkyl group, a C3 to C10 branched alkyl group, a C3 to C10 cyclic alkyl group, a C5 to C12 aryl group, a C2 to C10 linear or branched alkenyl group and a C2 to C10 linear or branched alkynyl group,
• a C1-C10 alkyl substituted with
• or
• II. a compound of Formula II:
• wherein:
• (i) m=0-20,
• (ii) n=0-20,
• (iii) R3 is selected from the group of hydrogen, a C1 to C10 linear alkyl group, a C1 to C10 linear alkyl group substituted with fluorine, a nitrogen-containing group, an oxygen-containing group, a C3 to C10 branched alkyl group, a C3 to C10 cyclic alkyl group, a C5 to C12 aryl group, a C2 to C10 linear or branched alkenyl group and a C2 to C10 linear or branched alkynyl group,
• Z1 and Z2, and
• (iv) each of Ra and Rb is independently selected from a C1 to C10 linear alkyl group, a C3 to C10 branched alkyl group, a C3 to C10 cyclic alkyl group, a C5 to C12 aryl group, a C2 to C10 linear or branched alkenyl group and a C2 to C10 linear or branched alkynyl group,
• a C1-C10 alkyl substituted with
• (v) Z1 and Z2 are each independently selected from:
• and
• III. an aqueous solvent,
• wherein the composition is free of ammonium ions.