Systems and processes for forming three-dimensional integrated circuits

A process for forming a three-dimensional circuit on a substrate, the process comprising:

• providing the substrate, the substrate comprising
• a first circuit layer,
• a second circuit layer,
• a seed region, and
• an isolating layer interposed between the first and second circuit layers and including a through-hole disposed therethrough,
• wherein the second circuit layer communicates with the first circuit layer via the through-hole, and wherein the seed region is disposed within the through-hole and has a crystalline surface, and wherein the second circuit layer includes a microstructure that exhibits electronic properties unsuitable for forming circuit features therein;
• and
• heating the second circuit layer no higher than a submelt temperature thereof in order to initiate and propagate crystal growth from the seed region, thereby transforming the initial microstructure of the second circuit layer into a transformed microstructure that exhibits electronic properties suitable for forming circuit features therein.