Mixed deposition and etching processes for improved gap filling

Abstract

A method is provided for bottom-up gap filling of substrate features using a metal halide precursor, while simultaneously introducing a reducing agent and a halogen-containing etchant into the process chamber at a process temperature of less than 400°C. Using a selective gap-filling process, features can be filled with transition metals, including molybdenum or tungsten. Some methods involve the use of a metal halide precursor and a halogen-containing etchant, where both the precursor and etchant contain the same halogen and / or pulsed plasma power.

Claims

1. A method for performing bottom-up gap filling of substrate features, (a) A step of providing a substrate including a plurality of features in a process chamber, wherein each feature includes a feature opening and a feature bottom, (b) The step of introducing a metal halide precursor into the process chamber, (c) The step of introducing a reducing agent into the process chamber, (d) The step of introducing a halogen-containing etching agent into the process chamber Includes, (d) occurs during the duration of (c), the duration of (d) being the same as or shorter than the duration of (c), thereby the metal halide precursor reacting with the reducing agent to deposit a metal film on the feature, and the halogen-containing etching agent preferentially etching the metal film near the feature opening over the metal film near the bottom of the feature. method.

2. The method according to claim 1, wherein the metal film comprises molybdenum or tungsten.

3. The method according to claim 1, wherein the reducing agent is hydrogen.

4. The method according to claim 1, wherein the halogen-containing etching agent and the metal halide precursor contain the same halogen.

5. The method according to claim 1, wherein the metal halide precursor comprises a molybdenum halide precursor or a tungsten halide precursor.

6. The halogen-containing etching agent is HCl, Cl ２ MoCl ５ HBr, HF, F ２ MoF ６ The method according to claim 1, including, or a combination thereof.

7. The method according to claim 5, wherein the halide molybdenum precursor comprises halide molybdenum, molybdenum oxyhalide, or a combination thereof.

8. The method according to claim 7, wherein the molybdenum halogenate includes molybdenum dichloride, molybdenum trichloride, molybdenum tetrachloride, molybdenum pentachloride, molybdenum hexachloride, molybdenum hexafluoride, or molybdenum fluoride.

9. The method according to claim 7, wherein the molybdenum oxyhalide includes molybdenum dichloride, molybdenum tetrachloride, molybdenum tetrafluoride, or molybdenum dibromide.

10. The method according to claim 5, wherein the tungsten halide precursor includes tungsten hexafluoride, tungsten pentafluoride, tungsten hexachloride, tungsten pentachloride, or a combination thereof.

11. The method according to claim 1, wherein the ratio of the reducing agent to the etching agent may be about 10:1 to about 1:

10.

12. The method according to claim 1, wherein the concentration of the etching agent increases or decreases during (d).

13. The method according to claim 1, wherein the duration of (b) is the same as the duration of (c).

14. The method according to claim 1, wherein the substrate is not removed from the processing chamber during any of operations (a) to (d) or in any of those operations.

15. The method according to claim 1, wherein the bottom-up gap filling is carried out by atomic layer deposition, plasma-enhanced atomic layer deposition, pulsed chemical vapor deposition, or plasma-enhanced chemical vapor deposition.

16. The method according to claim 1, wherein the temperature of the process chamber is maintained at less than approximately 400°C.

17. The method according to claim 16, wherein the temperature of the process chamber is maintained at approximately 200°C to approximately 300°C, and the process chamber has a pressure of less than approximately 500 Torr.

18. An apparatus for filling features on a semiconductor substrate, wherein the apparatus is One or more process chambers, One or more gas inlets to the process chamber and associated flow control hardware, A controller having at least one processor and memory Includes, The at least one processor and the memory are connected to each other in a way that allows them to communicate with one another. The at least one processor is at least operably connected to the associated flow control hardware, The memory stores computer executable instructions for controlling at least one processor to control at least the associated flow control hardware. Computer executable instructions are, (a) Causes the introduction of a metal halide precursor into the process chamber, (b) Causes the introduction of a reducing agent into the process chamber, (c) Causes the introduction of a halogen-containing etching agent into the process chamber, (c) occurs during the duration of (b), and the duration of (c) is the same as or shorter than the duration of (b). Device.

19. The apparatus according to claim 18, further comprising a plasma generator for providing pulsed plasma to one or more process chambers.

20. A method for performing bottom-up gap filling of substrate features, (a) A step of providing a substrate including a plurality of features in a process chamber, wherein each feature includes a feature opening and a feature bottom, (b) The step of introducing a metal halide precursor into the process chamber, (c) The step of introducing a reducing agent into the process chamber, (d) The step of introducing a halogen-containing etching agent into the process chamber Includes, (c) occurs during the duration of (d), the duration of (c) is the same as or shorter than the duration of (d), thereby the metal halide precursor reacts with the reducing agent to deposit a metal film on the feature, and the halogen-containing etching agent preferentially etches the metal film near the feature opening with respect to the metal film near the bottom of the feature. method.

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