Split substrate interposer

A method of forming an interposer, the method comprising:

• forming a first wiring plane on a front side surface of a first substrate, the first substrate having a backside surface opposite the front side surface, the first wiring plane including electrical contacts on a top surface of the first wiring plane;
• forming vias in the first substrate that extend from the backside surface of the first substrate to the first wiring plane;
• forming a second wiring plane on the front side surface of a second substrate, the second substrate having a backside surface opposite the front side surface, the second wiring plane including electrical contacts;
• and
• positioning the second substrate in contact with the first substrate such that the electrical contacts of the second wiring plane are aligned to be in contact with the vias in the first substrate.

An interposer comprising:

• a first substrate comprising first bulk material having a first TSV extending through the first bulk material, and a first wiring plane formed on the first bulk material in electrical contact with the first TSV;
• a second substrate comprising second bulk material having a second TSV extending through the second bulk material;
• and
• a first join interface connecting the first and second substrates such that the first wiring plane of the first substrate physically contacts the second substrate and the first TSVs are electrically connected to the second TSVs through the wiring plane.