Semiconductor device and method for manufacturing the same
A semiconductor device and a method for manufacturing a semiconductor device are provided. The semiconductor device includes a substrate, a gate stack, a gate spacer, a conductive feature, and a conductive cap. The substrate has a source/drain region. The gate stack is on the substrate. The gate spacer is alongside the gate stack. The conductive feature is on the source/drain region. The conductive cap is on the conductive feature and has a top in a position lower than a top of the gate spacer.
1. A semiconductor device, comprising:
a substrate having a source/drain region;
a gate stack on the substrate;
a gate spacer alongside the gate stack;
a conductive feature on the source/drain region; and
a conductive cap on the conductive feature and having a top in a position lower than a top of the gate spacer.
2. The semiconductor device of claim 1 , wherein the conductive cap is in contact with the gate spacer.
3. The semiconductor device of claim 1 , further comprising:
a first dielectric mask on the conductive cap and in contact with the gate spacer.
4. The semiconductor device of claim 3 , further comprising:
a second dielectric mask stack on the gate stack and having a height greater than a height of the first dielectric mask.
5. The semiconductor device of claim 3 , further comprising:
an etch stop layer across the gate spacer, wherein the first dielectric mask is between the etch stop layer and the conductive cap.
6. The semiconductor device of claim 1 , further comprising:
a barrier layer in contact with the conductive cap and wrapping around the conductive feature.
7. The semiconductor device of claim 1 , wherein the conductive cap comprises a material different from a material of the conductive feature.
8. A semiconductor device, comprising:
a substrate having a source/drain region;
a first gate stack on the substrate;
a first gate spacer alongside the first gate stack;
a conductive cap separated from the first gate stack by the first gate spacer;
a conductive feature between the source/drain region and the conductive cap;
a second gate stack on the substrate;
a second gate spacer alongside the second gate stack, wherein the conductive cap is separated from the second gate stack by the second gate spacer; and
a dielectric mask on the conductive cap and in contact with the first gate spacer and the second gate spacer.
9. The semiconductor device of claim 8 , wherein the conductive cap is in contact with the first gate spacer and the second gate spacer.
10. The semiconductor device of claim 8 , further comprising:
a first contact plug on the first gate stack; and
a second contact plug on the conductive cap and shorter than the first contact plug.
11. The semiconductor device of claim 8 , further comprising:
a first contact plug forming a first interface with the first gate stack; and
a second contact plug forming a second interface with the conductive cap, wherein the first interface is in a position lower than the second interface.
12. The semiconductor device of claim 11 ,
wherein the second contact plug extends to above the second gate stack.
13. The semiconductor device of claim 8 , wherein the conductive cap and the first gate stack are respectively in contact with opposite sidewalls of the first gate spacer.
14. The semiconductor device of claim 8 , wherein the conductive cap has a top surface lower than a top surface of the first gate spacer.
15. The semiconductor device of claim 8 , wherein the dielectric mask has a top surface level with a top surface of the first gate spacer.
16. A method for manufacturing a semiconductor device, comprising:
forming a source/drain region in a substrate and a gate stack on the substrate;
forming a first hard mask on the gate stack;
forming a conductive feature on the source/drain region;
forming a second hard mask above the conductive feature;
etching the second hard mask to form a second via opening;
after etching the second hard mask, etching the first hard mask to form a first via opening to expose the gate stack; and
forming a first contact plug and a second contact plug in the first via opening and the second via opening, respectively.
17. The method of claim 16 , further comprising:
forming a conductive cap on the conductive feature prior to forming the second hard mask.
18. The method of claim 17 , wherein etching the second hard mask is performed until the conductive cap is exposed.
19. The method of claim 16 , further comprising:
performing an etch back process on the conductive feature; and
after performing the etch back process, forming a conductive cap on the conductive feature.
20. The method of claim 19 , wherein forming the conductive cap is performed such that a top surface of the conductive cap is in a position lower than a top surface of the first hard mask.