Devices, systems, and methods for stacked die packages

A method, comprising:

• forming a plurality of grooves in a first wafer including a plurality of first chips;
• bonding the first wafer to a second wafer including a plurality of second chips to form a bonded structure;
• thinning the first wafer in the bonded structure to remove the plurality of grooves;
• and
• dicing the thinned bonded structure to form a plurality of first chip stacks, each first chip stack including one of the first plurality of chips and one of the second plurality of chips.

A package, comprising:

• a first chip stack including:
• a first chip including first bonding structures;
• a second chip including second bonding structures facing the first bonding structures and bonded to the first bonding structures;
• and
• a first electrical contact on the second chip, wherein the first electrical contact does not overlap with the first chip in a plan view;
• and
• a second chip stack adhered to the first chip stack and including:
• a third chip including third bonding structures;
• a fourth chip including fourth bonding structures facing the third bonding structures and bonded to the third bonding structures;
• and
• a second electrical contact on the fourth chip, wherein the second electrical contact does not overlap with the third chip in the plan view;
• and
• a support substrate that supports the first chip stack and the second chip stack.