Method for controlling a thickness of a first layer and method for adjusting the thickness of different first layers
View Patent ↗A method for controlling a thickness of a first layer of an electrical contact of a semiconductor device, whereby the semiconductor device comprises a semiconductor layer, a first layer and a second layer, whereby at least a part of the semi-conductor layer is covered with the first layer, whereby at least a part of the first layer is covered with the second layer, whereby the second layer is exposed to a plasma gas, whereby an upper face of the first layer adjacent to the second layer is treated by the plasma gas and an interlayer is generated between the first and the second layer reducing the thickness of the first layer.
1. A method for controlling a thickness of a first layer of an electrical contact of a semiconductor device, comprising:
forming the first layer on a substrate of the semiconductor device;
covering at least a part of the first layer with a second layer;
exposing the second layer to a gas plasma treatment, wherein the gas plasma passes through the second layer and reacts with a surface of the first layer adjacent to the second layer; and
forming an interlayer between the first layer and the second layer, the interlayer being formed by the reaction between the gas plasma and the surface of the first layer adjacent to the second layer, wherein forming the interlayer reduces the thickness of the first layer.
2. The method according to claim 1 , whereby the gas plasma comprises hydrogen and nitrogen.
3. The method according to claim 1 , whereby the first layer comprises cobalt.
4. The method according to claim 1 , whereby the first layer comprises nickel.
5. The method according to claim 1 , whereby the first layer comprises tungsten.
6. The method according to claim 1 , whereby the gas plasma comprises ammonia.
7. The method according to claim 1 , whereby the gas plasma comprises argon.
8. The method according to claim 1 , whereby the gas plasma comprises any combination of hydrogen, nitrogen, ammonia, and argon.
9. The method according to claim 1 , whereby the second layer is deposited by a physical vapour deposition process.
10. The method according to claim 1 , whereby the second layer is deposited by a metal-organic chemical vapour deposition process.
11. The method according to claim 1 , whereby the gas plasma treatment is processed with an electrical power between 300 and 3000 W.
12. The method according to claim 1 , whereby the gas plasma treatment is processed with a duration between 5 and 60 seconds.
13. The method according to claim 1 , whereby the substrate is a metal layer.
14. The method according to claim 1 , whereby the first layer comprises titanium.
15. The method according to claim 14 , whereby the titanium is deposited by physical vapour deposition.
16. The method according to claim 14 , whereby the second layer comprises titanium nitride.
17. The method according to claim 16 , whereby the titanium nitride is deposited by a chemical vapour deposition.
18. The method according to claim 1 , whereby the substrate is a semiconductor layer.
19. The method according to claim 18 , whereby a memory device is fabricated.
20. The method according to claim 18 , whereby a logic device is fabricated.
21. The method according to claim 20 , whereby the gas plasma comprises argon.
22. A method for reducing differences in thickness of a first layer of an electrical contact deposited in each of a plurality of contact holes of different aspect ratios of a device, comprising:
depositing the first layer in each of the plurality of contact holes formed on a substrate, wherein the first layer is formed in each of the plurality of contact holes with varying thicknesses;
depositing a second layer on the first layer in each of the plurality of contact holes;
exposing the second layer in each of the plurality of contact holes to a gas plasma treatment, wherein the gas plasma passes through the second layer and reacts with a surface of the first layer adjacent to the second layer; and
forming an interlayer between the first layer and the second layer in each of the contact holes, the interlayer being formed by the reaction between the gas plasma and the surface of the first layer adjacent to the second layer, wherein forming the interlayer reduces the thickness of the first layer in each of the contact holes and reduces differences in thickness of the first layer in each of the plurality of contact holes by forming a relatively thicker interlayer in contact holes comprising a relatively thicker first layer.
23. The method according to claim 22 , whereby the gas plasma comprises hydrogen and nitrogen.
24. The method according to claim 22 , whereby the first layer comprises cobalt.
25. The method according to claim 22 , whereby the first layer comprises nickel.
26. The method according to claim 22 , whereby the first layer comprises tungsten.
27. The method according to claim 22 , whereby the gas plasma comprises ammonia.
28. The method according to claim 22 , whereby the first layer is deposited by a physical vapour deposition process.
29. The method according to claim 22 , whereby the second layer is deposited by a chemical vapour deposition process.
30. The method according to claim 22 , whereby the gas plasma treatment is processed with an electrical power between 300 and 3000 W.
31. The method according to claim 22 , whereby the gas plasma treatment is processed with a duration between 5 and 60 seconds.
32. The method according to claim 22 , whereby the substrate is a semiconductor layer and the device is a semiconductor device.
33. The method according to claim 22 , whereby the substrate is a metallic layer.
34. The method according to claim 22 , whereby the gas plasma treatment is processed with relatively greater impact on contact holes having a relatively thicker first layer and with a relatively smaller impact on contact holes having a relatively thinner first layer.
35. The method according to claim 22 , whereby the first layer comprises titanium.
36. The method according to claim 35 , whereby the titanium is deposited by plasma vapour deposition.
37. The method according to claim 35 , whereby the second layer comprises titanium nitride.
38. The method according to claim 37 , whereby the titanium nitride is deposited by chemical vapour deposition.
39. A method for controlling thickness of a first layer of an electrical contact of a device, comprising:
forming the first layer on a substrate of the device;
forming a second layer on at least a portion of the first layer; and
exposing the second layer to a gas plasma, wherein the gas plasma passes through the second layer and reacts with a surface of the first layer adjacent to the second layer, the reaction between the gas plasma and the surface of the first layer adjacent to the second layer reducing the thickness of the first layer to a predetermined thickness.