Semiconductor device including a porous dielectric layer, and method of forming the semiconductor device
A semiconductor device includes a porous dielectric layer including a recessed portion, a conductive layer formed in the recessed portion, and a cap layer formed on the porous dielectric layer and on the conductive layer in the recessed portion, an upper surface of the porous dielectric layer being exposed through a gap in the cap layer.
1. A method of forming a semiconductor device, the method comprising:
forming a pore-filled porous dielectric layer including a recessed portion;
forming a conductive layer in the recessed portion;
forming a cap layer on the pore-filled porous dielectric layer and on the conductive layer; and
removing at least a portion of the cap layer to expose an upper surface of the pore-filled porous dielectric layer through a gap in the cap layer to provide an exposed upper surface of the pore-filled porous dielectric layer.
2. The method of claim 1 , further comprising:
performing a treatment to remove one or more pore fillers of the pore-filled porous dielectric layer through the exposed upper surface of the pore-filled porous dielectric layer.
3. The method of claim 2 , wherein:
the treatment comprises a heat treatment;
a temperature of the heat treatment is in a range of 200 degrees Celsius to 450 degrees Celsius; and
a duration of the heat treatment is in a range of 1 minute to 30 minutes.
4. The method of claim 2 , wherein the treatment comprises a UV treatment.
5. The method of claim 1 , wherein forming the conductive layer comprises:
depositing a metal on the pore-filled porous dielectric layer;
polishing the metal; and
etching a top portion of the metal in the recessed portion.
6. A method of forming a semiconductor device, the method comprising:
forming a conductive layer in a first recessed portion of a pore-filled porous dielectric layer;
removing a top portion of the conductive layer to form a second recessed portion;
depositing a cap layer on the pore-filled porous dielectric layer and an upper surface of the conductive layer;
depositing an interlayer dielectric on the cap layer; and
polishing the interlayer dielectric and the cap layer to form a gap in the cap layer such that an upper surface of the pore-filled porous dielectric layer is exposed through the gap to provide an exposed upper surface of the pore-filled porous dielectric layer.
7. The method of claim 6 , further comprising:
performing a treatment to remove one or more pore fillers of the pore-filled porous dielectric layer through the exposed upper surface of the pore-filled porous dielectric layer.
8. The method of claim 7 , wherein:
the treatment comprises a heat treatment;
a temperature of the heat treatment is in a range of 200 degrees Celsius to 450 degrees Celsius; and
a duration of the heat treatment is in a range of 1 minute to 30 minutes.
9. The method of claim 7 , wherein the treatment comprises a UV treatment.
10. The method of claim 6 , wherein an upper surface of the interlayer dielectric is co-planar with an upper surface of the cap layer and the upper surface of the pore-filled porous dielectric layer.
11. The method of claim 6 , wherein removing the top portion of the conductive layer comprises etching the conductive layer.
12. The method of claim 6 , wherein removing the top portion of the conductive layer comprises etching the conductive layer, and a portion of the pore-filled porous dielectric layer along sidewalls of the first recessed portion.
13. The method of claim 12 , wherein the second recessed portion is wider than the first recessed portion.
14. The method of claim 1 , wherein:
an upper surface of the cap layer includes a concave portion; and
depositing an interlayer dielectric on the cap layer comprises depositing the interlayer dielectric in the concave portion of the cap layer.
15. The method of claim 14 , wherein an upper surface of the interlayer dielectric is co-planar with the upper surface of the cap layer and the upper surface of the pore-filled porous dielectric layer.
16. The method of claim 1 , wherein an upper portion of the cap layer has a width which is greater than a width of a lower portion of the cap layer.
17. The method of claim 6 , wherein:
an upper surface of the cap layer includes a concave portion; and
depositing an interlayer dielectric on the cap layer comprises depositing the interlayer dielectric in the concave portion of the cap layer.
18. The method of claim 17 , wherein an upper surface of the interlayer dielectric is co-planar with the upper surface of the cap layer and an upper surface of the pore-filled porous dielectric layer.
19. The method of claim 6 , wherein an upper portion of the cap layer has a width which is greater than a width of a lower portion of the cap layer.