Formation method of semiconductor device with gate spacer
A structure and a formation method of a semiconductor device structure are provided. The method includes forming a gate stack over a semiconductor substrate. The method also includes forming a sealing layer over a sidewall of the gate stack using an atomic layer deposition process. The atomic layer deposition process includes alternately and sequentially introducing a first silicon-containing precursor gas and a second silicon-containing precursor gas over the sidewall of the gate stack to form the sealing layer. The second silicon-containing precursor gas has a different atomic concentration of carbon than that of the first silicon-containing precursor gas. The method further includes partially removing the sealing layer to form a sealing element over the sidewall of the gate stack.
1. A method for forming a semiconductor device structure, comprising:
forming a gate stack over a semiconductor substrate;
forming a sealing layer over a sidewall of the gate stack using an atomic layer deposition process in a process chamber, wherein the atomic layer deposition process comprises:
alternately and sequentially introducing a first silicon-containing precursor gas and a second silicon-containing precursor gas over the sidewall of the gate stack to form the sealing layer, wherein the second silicon-containing precursor gas has a different atomic concentration of carbon than that of the first silicon-containing precursor gas, and
removing an excess portion of the first silicon-containing precursor gas from the process chamber before the second silicon-containing gas is introduced; and
partially removing the sealing layer to form a sealing element over the sidewall of the gate stack.
2. The method for forming a semiconductor device structure as claimed in claim 1 , wherein the second silicon-containing precursor gas has a greater atomic concentration of carbon than that of the first silicon-containing precursor gas.
3. The method for forming a semiconductor device structure as claimed in claim 1 , further comprising:
introducing at least one first modifying reactive media after removing the excess portion of the first silicon-containing precursor gas from the process chamber and before introducing the second silicon-containing precursor gas; and
introducing at least one second modifying reactive media after introducing the second silicon-containing precursor gas and before introducing the first silicon-containing precursor gas again.
4. The method for forming a semiconductor device structure as claimed in claim 3 , wherein introducing the at least one first modifying reactive media comprises:
introducing an oxygen-containing media;
introducing a nitrogen-containing media; and
introducing a carbon-containing media.
5. The method for forming a semiconductor device structure as claimed in claim 3 , wherein introducing the at least one second modifying reactive media comprises:
introducing an oxygen-containing media;
introducing a nitrogen-containing media; and
introducing a carbon-containing media.
6. The method for forming a semiconductor device structure as claimed in claim 1 , wherein the first silicon-containing precursor gas comprises a silicon-halogen bonding, a silicon-nitrogen bonding, a silicon-hydrogen bonding, or a combination thereof.
7. The method for forming a semiconductor device structure as claimed in claim 1 , wherein the second silicon-containing precursor gas comprises a silicon-carbon bonding.
8. The method for forming a semiconductor device structure as claimed in claim 7 , wherein the second silicon-containing precursor gas further comprises a silicon-halogen bonding, a silicon-nitrogen bonding, a silicon-hydrogen bonding, or a combination thereof.
9. The method for forming a semiconductor device structure as claimed in claim 1 , further comprising:
forming a lightly doped region under the sealing layer;
forming a spacer layer over the sealing layer; and
partially removing the spacer layer to form a spacer element over the sealing element.
10. The method for forming a semiconductor device structure as claimed in claim 9 , wherein the spacer layer is formed using a second atomic layer deposition process, wherein the second atomic layer deposition process comprises alternately and sequentially introducing a third silicon-containing precursor gas and a fourth silicon-containing precursor gas over the sidewall of the gate stack to form the spacer layer, wherein the fourth silicon-containing precursor gas has a different atomic concentration of carbon than that of the third silicon-containing precursor gas.
11. The method for forming a semiconductor device structure as claimed in claim 10 , wherein the first silicon-containing precursor gas and the third silicon-containing precursor gas have the same composition, and the second silicon-containing precursor gas and the fourth silicon-containing precursor gas have the same composition.
12. A method for forming a semiconductor device structure, comprising:
forming a gate stack over a semiconductor substrate;
forming a sealing layer over a sidewall of the gate stack using an atomic layer deposition process in a process chamber, wherein the atomic layer deposition process comprises:
repeatedly introducing a first silicon-containing precursor gas over the sidewall of the gate stack to form a first portion of the sealing layer,
removing an excess portion of the first silicon-containing precursor gas from the process chamber before the first silicon-containing precursor gas is introduced again, and
repeatedly introducing a second silicon-containing precursor gas over the sidewall of the gate stack to form a second portion of the sealing layer over the first portion of the sealing layer, wherein the second silicon-containing precursor gas has a different atomic concentration of carbon than that of the first silicon-containing precursor gas; and
partially removing the sealing layer to form a sealing element over the sidewall of the gate stack.
13. The method for forming a semiconductor device structure as claimed in claim 12 , further comprising:
introducing at least one first modifying reactive media after removing the excess portion of the first silicon-containing precursor gas from the process chamber and before introducing the first silicon-containing precursor gas again; and
introducing at least one second modifying reactive media after introducing the second silicon-containing precursor gas and before introducing the second silicon-containing precursor gas again.
14. The method for forming a semiconductor device structure as claimed in claim 13 , wherein introducing the at least one first modifying reactive media comprises:
introducing an oxygen-containing media;
introducing a nitrogen-containing media; and
introducing a carbon-containing media.
15. The method for forming a semiconductor device structure as claimed in claim 13 , wherein introducing the at least one second modifying reactive media comprises:
introducing an oxygen-containing media;
introducing a nitrogen-containing media; and
introducing a carbon-containing media.
16. The method for forming a semiconductor device structure as claimed in claim 12 , further comprising forming a spacer layer over the sealing layer using a second atomic layer deposition process, and the second atomic layer deposition process comprises repeatedly introducing a third silicon-containing precursor gas over the sidewall of the gate stack to form a first portion of the spacer layer over the second portion of the sealing layer; and
repeatedly introducing a fourth silicon-containing precursor gas over the sidewall of the gate stack to form a second portion of the spacer layer over the first portion of the spacer layer, wherein the fourth silicon-containing precursor gas has a different atomic concentration of carbon than that of the third silicon-containing precursor gas.
17. The method for forming a semiconductor device structure as claimed in claim 16 , wherein the third silicon-containing precursor gas and the first silicon-containing precursor gas have the same composition.
18. The method for forming a semiconductor device structure as claimed in claim 12 , further comprising alternately and sequentially introducing a third silicon-containing precursor gas and a fourth silicon-containing precursor gas over the sidewall of the gate stack to form a spacer layer over the sealing layer, wherein the fourth silicon-containing precursor gas has a different atomic concentration of carbon than that of the third silicon-containing precursor gas.
19. A method for forming a semiconductor device structure, comprising:
forming a gate stack over a semiconductor substrate;
forming a sealing layer over a sidewall of the gate stack using an atomic layer deposition process in a process chamber, wherein the atomic layer deposition process comprises:
alternately and sequentially introducing a first silicon-containing precursor gas and a second silicon-containing precursor gas for at least twice over the sidewall of the gate stack to form the sealing layer, wherein the second silicon-containing precursor gas includes a silicon-carbon bonding, and the first silicon-containing precursor gas does not include any silicon-carbon bonding; and
partially removing the sealing layer to form a sealing element over the sidewall of the gate stack.
20. The method for forming a semiconductor device structure as claimed in claim 19 , further comprising:
introducing at least one first modifying reactive media after introducing the first silicon-containing precursor gas and before introducing the second silicon-containing precursor gas; and
introducing at least one second modifying reactive media after introducing the second silicon-containing precursor gas and before introducing the first silicon-containing precursor gas again.