Semiconductor structure including multiple barrier layers and method for forming the same
The present disclosure provides a semiconductor structure. The semiconductor structure includes: a substrate; a transistor on the substrate; a first dielectric layer over the transistor; a second dielectric layer over the first dielectric layer; a barrier layer extending from the second dielectric layer to the first dielectric layer; and a conductive structure separated from the second dielectric layer and the first dielectric layer by the barrier layer. The barrier layer includes: a first layer, including titanium or tantalum along inner sidewalls of the first dielectric layer and the second dielectric layer; a second layer, being an oxide of titanium or tantalum and over the first layer; and a third layer, including cobalt and over the second layer.
1 . A method of manufacturing a semiconductor structure, comprising:
providing a substrate;
forming a transistor on the substrate;
forming a first dielectric layer over the transistor;
forming a second dielectric layer over the first dielectric layer;
etching the first dielectric layer to form a first contact hole;
etching the second dielectric layer to form a second contact hole connected with the first contact hole;
forming a barrier layer within the first contact hole and the second contact hole; and
depositing a conductive material on the barrier layer to fill the first contact hole and the second contact hole, wherein the forming of the barrier layer comprises:
forming a first layer including titanium or tantalum along inner sidewalls of the first dielectric layer and the second dielectric layer under a first pressure; and
introducing a source gas including cobalt to the first layer under a second pressure greater than the first pressure to form a second layer comprising an oxide of the first layer and a third layer comprising a cobalt-containing layer including a portion of the oxide.
2 . The method of claim 1 , wherein the first pressure is between about 10 −8 torr and about 10 −7 torr.
3 . The method of claim 1 , wherein the second pressure is greater than about 10 −7 torr.
4 . The method of claim 1 , wherein the second layer and the third layer are in-situ formed.
5 . The method of claim 1 , wherein the first layer is formed in a first chamber and the third layer is formed in a second chamber different from the first chamber, and the substrate is transferred from the first chamber to the second chamber without breaking vacuum.
6 . The method of claim 5 , wherein the first layer is oxidized in the second chamber.
7 . The method of claim 1 , wherein the second layer binds the third layer after the third layer is formed.
8 . A method of manufacturing a semiconductor structure, comprising:
forming a transistor on a substrate;
forming a first dielectric layer over the transistor;
forming a second dielectric layer over the first dielectric layer;
recessing the first dielectric layer and the second dielectric layer to form a contact hole;
conformally forming a tantalum-containing layer within the contact hole under a first pressure;
introducing a source gas including cobalt to the tantalum-containing layer to form an oxide of the tantalum-containing layer and a cobalt-containing layer including a portion of the oxide; and
filling the contact hole by depositing a conductive material on the cobalt-containing layer.
9 . The method of claim 8 , wherein the oxide is simultaneously formed when forming the cobalt-containing layer.
10 . The method of claim 8 , wherein the oxide is formed in-situ during the formation of the cobalt-containing layer.
11 . The method of claim 8 , wherein the oxide has a strong affinity to the cobalt-containing layer.
12 . The method of claim 8 , wherein the oxide is crystalline.
13 . The method of claim 12 , wherein the oxide of the tantalum-containing layer has an atomic ratio of oxygen to tantalum less than about 1.
14 . The method of claim 12 , wherein the oxide of the tantalum-containing layer has an atomic ratio of oxygen to tantalum more than about 0.02.
15 . A method of manufacturing a semiconductor structure, comprising:
forming a dielectric layer over a transistor;
recessing the dielectric layer to form a contact hole;
conformally forming a barrier layer within the contact hole; and
depositing a conductive material on the barrier layer to fill the contact hole, wherein the forming of the barrier layer includes:
forming a first layer including titanium along inner sidewalls of the dielectric layer under a first pressure; and
introducing a source gas including cobalt to the first layer to form a second layer comprising an oxide of the first layer and a third layer comprising a cobalt-containing layer including a portion of the oxide.
16 . The method of claim 15 , wherein a thickness ratio between the first layer and the second layer is about 5:1.
17 . The method of claim 15 , wherein a thickness ratio between the second layer and the third layer is about 1:2.
18 . The method of claim 15 , wherein the second layer is crystalline.
19 . The method of claim 15 , wherein the second layer is formed in-situ during the formation of the third layer.
20 . The method of claim 15 , wherein the first layer, the second layer and the third layer are formed in a same chamber.