Methods and structure for carrier-less thin wafer handling

A method of forming a microelectronic assembly, comprising:

• removing material exposed at portions of a surface of a substrate to form a processed substrate having a plurality of thinned portions separated by integral supporting portions of the processed substrate, the supporting portions having a thickness greater than a thickness of the thinned portions, the thinned portions including electrically conductive interconnects extending in a direction of the thickness of the thinned portions and exposed at the surface;
• forming a dielectric layer on the thinned portions;
• forming openings extending through the dielectric layer, the interconnects being exposed within the openings;
• depositing an electrically conductive material within the openings;
• and
• removing material of the processed substrate so as to planarize a surface of the dielectric layer relative to at least one of the supporting portions or material of the processed substrate overlying the supporting portions.