Die warpage control for thin die assembly

A semiconductor package comprising:

• a package substrate;
• a semiconductor die attached to the package substrate, the die having a plurality of contacts on a front side to attach to the package substrate and a thinned semiconductor substrate on a backside of the die to carry the contacts, the front side being opposite the back side, the back side having a semiconductor substrate and the front side having components formed over the semiconductor substrate in front side layers that are connected to the contacts;
• and
• a backside layer over the backside of the semiconductor die to resist warpage of the die when the die is heated.