Anisotropic conductive film with carbon-based conductive regions having void space and related semiconductor device assemblies and methods

A semiconductor device assembly, comprising:

• a semiconductor die comprising conductive structures spaced along a surface of the semiconductor die;
• an additional semiconductor die comprising additional conductive structures spaced along a surface of the additional semiconductor die;
• and
• an anisotropic conductive film interposed between the semiconductor die and the additional semiconductor die, the anisotropic conductive film comprising:
• a pattern of discrete regions within a substantially continuous region of at least one adhesive dielectric material, each one of the discrete regions of the pattern being mutually laterally spaced from other discrete regions by at least one predetermined pitch, the discrete regions comprising a conductive carbon-based material, the discrete regions extending partially through the adhesive dielectric material, and the adhesive dielectric material above and below the discrete regions, and
• at least some of the discrete regions individually defining a void space within the conductive carbon-based material, the void space extending into the conductive carbon-based material from a surface of the conductive carbon-based material.

A method for forming an anisotropic conductive film structure, the method comprising:

• forming a precursor structure, comprising:
• forming a dielectric material on a sacrificial base material;
• defining discrete openings in the dielectric, material, the discrete openings being mutually laterally spaced by at least one predetermined pitch;
• forming a seed material in the discrete openings, and conformally forming a conductive carbon-based material on the seed material, in at least some of the discrete openings, the conductive carbon-based material defining a void space;
• forming an additional structure comprising an adhesive dielectric material on an additional base material;
• joining the precursor structure, on a surface thereof opposite the sacrificial base material, to the additional structure;
• removing the sacrificial base material;
• removing the dielectric material to form additional openings;
• and
• forming additional adhesive dielectric material in the additional openings to electrically insulate discrete regions comprising the conductive carbon-based material and the seed material, the discrete regions extending partially through the additional adhesive dielectric material and the adhesive dielectric material or the additional adhesive dielectric material above and below the discrete regions, at least some of the discrete regions each defining the void space within the conductive carbon-based material, the void space extending into the conductive carbon-based material from a surface of the conductive carbon-based material.