Low temperature hybrid bonding metallization
A semiconductor wafer, including a substrate, at least one via formed in the substrate, and copper electroplating inside the at least one via, where the copper electroplating comprises a first layer of nanotwin copper, and a second layer of bulk copper. Further, a method of making a semiconductor wafer, the method comprising providing a substrate; etching the substrate to form at least one via; and depositing copper electroplating inside the at least one via, wherein the copper electroplating comprises a first layer of nanotwin copper, and a second layer of bulk copper.
1 . A semiconductor wafer, comprising:
a substrate;
at least one via formed in the substrate; and
a copper electroplating inside the at least one via, wherein the copper electroplating comprises a first layer of nanotwin copper, and a second layer of bulk copper, wherein the bulk copper is fine grain copper.
2 . The semiconductor of claim 1 , wherein the first layer is deposited in the at least one via before the second layer is deposited in the via.
3 . The semiconductor of claim 2 , wherein the first layer extends above a top of the at least one via.
4 . The semiconductor of claim 1 , wherein the second layer is deposited in the via before the first layer is deposited in the at least one via.
5 . The semiconductor of claim 4 , wherein the second layer extends above a top of the at least one via.
6 . The semiconductor wafer of claim 4 , wherein the first layer of nanotwin copper provides a hybrid bonding interface, wherein the hybrid bonding interface comprises above 50% nanotwin copper.
7 . The semiconductor of claim 1 , wherein the second layer partially fills the at least one via; and the first layer partially fills the at least one via and extends above a top of the at least one via.
8 . The semiconductor wafer of claim 1 , wherein an aspect ratio of the at least one via and the substrate is about 0.1.
9 . A method of making a semiconductor wafer, the method comprising:
providing a substrate;
etching the substrate to form at least one via;
depositing a first layer of nanotwin copper inside the at least one via; and
depositing a second layer of bulk copper inside the at least one via, wherein the second layer of bulk copper is a fine grain copper.
10 . The method of claim 9 , wherein the first layer of nanotwin copper is deposited before depositing the second layer of bulk copper.
11 . The method of claim 9 , wherein the first layer of nanotwin copper extends above a top of the at least one via.
12 . The method of claim 9 , wherein the second layer of bulk copper is deposited before depositing the first layer of nanotwin copper.
13 . The method of claim 12 , wherein the second layer of bulk copper extends above a top of the at least one via.
14 . The method of claim 12 , wherein the method further comprises:
forming a hybrid bonding interface between the first layer of nanotwin copper and the second layer of bulk copper.
15 . The method of claim 14 , wherein the hybrid bonding interface comprises above 50% nanotwin copper.
16 . The method of claim 12 , further comprising:
after depositing the second layer of bulk copper, cleaning the second layer of bulk copper by applying an acid before depositing the first layer of nanotwin copper.
17 . The method of claim 16 , wherein cleaning the second layer of bulk copper further comprises applying an oxidizing agent.