Use of photoresist in substrate vias during backside grind

A structure and method of formation. The substrate has front and back surfaces on opposite sides of the substrate. The substrate has a backside portion extending from the back surface to a second depth into the substrate as measured from the front surface. At least one via is formed in the substrate and extends from the front surface to a via depth into the substrate. The via depth is specific to each via. The via depth of each via is less than an initial thickness of the substrate. The second depth does not exceed the minimum via depth of the via depths. Organic material (e.g., photoresist) is inserted into each via. The organic material is subsequently covered with a tape, followed by removal of the backside portion of the substrate. The tape is subsequently removed from the organic material, followed by removal of the organic material from each via.