Method of forming a conductive barrier layer within critical openings by a final deposition step after a re-sputter deposition
In forming a thin conductive layer in an interconnect structure by sputter deposition including a re-sputtering step, a flash deposition step is performed after the re-sputtering step to provide a sufficient layer thickness at critical locations, such as at positions of structure irregularities. The flash deposition step may be performed for a fixed process time so that less effort in process control is required while, at the same time, an increased reliability may be obtained compared to conventional approaches without a flash deposition.
1. A method, comprising:
sputter depositing a layer of conductive material within an opening formed in a dielectric layer;
re-sputtering a portion of said conductive material deposited within said opening;
sputter depositing additional portions of said conductive material within said opening; and
performing at least one additional re-sputtering process after the process of sputter depositing said additional portions of said conductive material within said opening.
2. The method of claim 1 , wherein sputter depositing additional portions of said conductive material is performed for a predefined time period.
3. The method of claim 2 , wherein said predefined time period ranges from approximately 1–5 seconds.
4. The method of claim 1 , wherein re-sputtering a portion of said conductive material is performed in a sputter ambient of a first state and sputter depositing said additional portions of said conductive material is performed in said sputter ambient being in a second state, a bias power of said second state being lower than a bias power of said first state.
5. The method of claim 4 , wherein a pressure in said sputter ambient in the first state is higher than a pressure of said second state.
6. The method of claim 1 , further comprising controlling at least one process parameter of a sputter ambient during the sputter deposition of said additional portions of said conductive material to adjust a deposition non-uniformity of said conductive material in said opening.
7. The method of claim 1 , further comprising controlling at least one process parameter of a sputter ambient during the sputter deposition of said additional portions of said conductive material to adjust a deposition rate for depositing said additional portions of said conductive material.
8. The method of claim 1 , wherein said conductive material comprises at least one of tantalum and tantalum nitride.
9. The method of claim 1 , wherein said conductive material comprises copper.
10. The method of claim 1 , wherein process parameters for sputter depositing said conductive material are substantially the same as for sputter depositing said additional portions of said conductive material.
11. A method of controlling a degree of coverage of an interconnect structure, the method comprising:
providing a substrate having formed therein at least one interconnect structure including vias and trenches;
forming a layer of conductive material above said interconnect structure by a re-sputter deposition technique;
sputter depositing said conductive material in a final flash based on at least one specified process parameter;
determining a thickness of said conductive material at a critical position in said interconnect structure;
determining a desired value of said at least one specified process parameter on the basis of said determined thickness; and
forming a layer of said conductive material on one or more substrates while using said desired value in said final flash of sputter deposition.
12. The method of claim 11 , wherein said thickness of said conductive material is determined on the basis of a plurality of different parameter settings of said at least one specified process parameter.
13. The method of claim 11 , wherein said at least one specified process parameter represents at least one of a bias power, a pressure of a deposition ambient during said final flash and a deposition time of said final flash.
14. A method, comprising:
sputter depositing a layer of conductive material within an opening formed in a dielectric layer;
re-sputtering with a first bias power a portion of said conductive material deposited within said opening;
sputter depositing additional portions of said conductive material within said opening with a second bias power for a fixed deposition time, said second bias power being less than said first bias power; and
performing at least one additional re-sputtenng process after the process of sputter depositing said additional portions of said conductive material within said opening.
15. The method of claim 14 , wherein said fixed deposition time is in the range of approximately 1–5 seconds.
16. The method of claim 14 , wherein a pressure during sputter depositing said additional portions is equal to or lower than a pressure during re-sputtering a portion of said conductive material.
17. The method of claim 14 , further comprising controlling at least one process parameter of a sputter ambient during the sputter deposition of said additional portions to adjust a deposition non-uniformity of said conductive material in said opening.
18. The method of claim 14 , further comprising controlling at least one process parameter of a sputter ambient during the sputter deposition of said additional portions to adjust a deposition rate for depositing said additional portions.
19. The method of claim 14 , wherein said conductive material comprises at least one of tantalum and tantalum nitride.
20. The method of claim 14 , wherein said conductive material comprises copper.
21. The method of claim 14 , wherein process parameters for sputter depositing said conductive material are substantially the same as for sputter depositing said additional portions.
22. A method of sputter depositing a conductive material over an interconnect structure, the method comprising:
sputter depositing a first layer of said conductive material;
performing a sequence including re-sputtering a portion of said conductive material and depositing a second layer of said conductive material, said sequence being a non-final sequence of sputter depositing said conductive material; and
performing a second sequence including re-sputtering a portion of said second layer of said conductive material and depositing a further layer of said conductive material.
23. The method of claim 22 , further comprising performing at least one re-sputter process after performing said sequence.
24. The method of claim 22 , wherein depositing of said second layer during said sequence is performed for a predefined time period.
25. The method of claim 24 , wherein said predefined time period is in the range of approximately 1–5 seconds.
26. The method of claim 22 , wherein a pressure during depositing said second layer is equal to or lower than a pressure during re-sputtering a portion of said conductive material.
27. The method of claim 22 , wherein a bias power supplied to a deposition ambient during depositing said second layer is lower than a bias power supplied during re-sputtering a portion of said conductive material.