In-situ thermoelectric cooling
Methods and structures for thermoelectric cooling of 3D semiconductor structures are disclosed. Thermoelectric vias (TEVs) to form a thermoelectric cooling structure. The TEVs are formed with an etch process similar to that used in forming electrically active through-silicon vias (TSVs). However, the etched cavities are filled with materials that exhibit the thermoelectric effect, instead of a conductive metal as with a traditional electrically active TSV. The thermoelectric materials are arranged such that when a voltage is applied to them, the thermoelectric cooling structure carries heat away from the interior of the structure from the junction where the thermoelectric materials are electrically connected.
1. A method of forming a cooling structure within a multiple die semiconductor structure, comprising
forming a conductive region within a first die of the multiple die semiconductor structure;
forming a first thermoelectric via within the multiple die semiconductor structure, such that it terminates at the conductive region and wherein the first thermoelectric via traverses a second die of the multiple die semiconductor structure;
forming a second thermoelectric via within the multiple die semiconductor structure, such that it terminates at the conductive region and wherein the second thermoelectric via traverses the second die of the multiple die semiconductor structure;
forming a first capture pad connected to the first thermoelectric via;
forming a second capture pad connected to the second thermoelectric via;
depositing a first thermoelectric material in the first thermoelectric via;
depositing a second thermoelectric material in the second thermoelectric via;
depositing an insulator layer on the second die of the multiple die semiconductor structure prior to forming the first thermoelectric via and the second thermoelectric via; and wherein:
depositing the first thermoelectric material in the first thermoelectric via comprises depositing the first thermoelectric material to a level below a top surface of the insulator layer; and wherein:
depositing the second thermoelectric material in the second thermoelectric via comprises depositing the first thermoelectric material to a level below a top surface of the insulator layer;
exposing a portion of the first thermoelectric via and the second thermoelectric via; and
forming a barrier layer on the exposed portion of the first thermoelectric via and the second thermoelectric via.
2. The method of claim 1 , wherein the plurality of through-silicon vias are formed prior to forming the first thermoelectric via and the second thermoelectric via.
3. The method of claim 1 , wherein the plurality of through-silicon vias are formed after forming the first thermoelectric via and the second thermoelectric via.
4. A method of forming a cooling structure within a multiple die semiconductor structure, comprising
forming a conductive region within a first die of the multiple die semiconductor structure;
forming a first thermoelectric via within the multiple die semiconductor structure, such that it terminates at the conductive region and wherein the first thermoelectric via traverses a second die of the multiple die semiconductor structure;
forming a second thermoelectric via within the multiple die semiconductor structure, such that it terminates at the conductive region and wherein the second thermoelectric via traverses the second die of the multiple die semiconductor structure;
depositing a first thermoelectric material in the first thermoelectric via;
depositing a second thermoelectric material in the second thermoelectric via;
depositing an insulator layer on the second die of the multiple die semiconductor structure prior to forming the first thermoelectric via and the second thermoelectric via; and wherein:
depositing the first thermoelectric material in the first thermoelectric via comprises depositing the first thermoelectric material to a level below a top surface of the insulator layer; and wherein:
depositing the second thermoelectric material in the second thermoelectric via comprises depositing the first thermoelectric material to a level below a top surface of the insulator layer;
exposing a portion of the first thermoelectric via and the second thermoelectric via; and
forming a barrier layer on the exposed portion of the first thermoelectric via and the second thermoelectric via.
5. The method of claim 4 , wherein the plurality of through-silicon vias are formed prior to forming the first thermoelectric via and the second thermoelectric via.
6. The method of claim 4 , wherein the plurality of through-silicon vias are formed after forming the first thermoelectric via and the second thermoelectric via.