Semiconductor processing systems having multiple plasma configurations

• US 10,256,079 B2
• Filed: 03/08/2013
• Issued: 04/09/2019
• Est. Priority Date: 02/08/2013
• Status: Active Grant

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Lubomirsky, Dmitry, Chen, Xinglong, Venkataraman, Shankar
• Primary Examiner(s): Dhingra, Rakesh K
• Application Number:
  US13/791,074
• Publication Number:
  US 20140227881A1
• Time in Patent Office: 2,223 Days
• Field of Search: 15634535, 118723 ME, 118723 ER
• CPC Class Codes: C23C 16/45565 Shower nozzles
• CPC Class Codes: C23C 16/505 using radio frequency discharges
• CPC Class Codes: C23C 16/54 Apparatus specially adapted for continuous coating
• CPC Class Codes: H01J 37/32357 Generation remote from the workpiece, e.g. down-stream
• CPC Class Codes: H01J 37/32422 Arrangement for selecting ions or species in the plasma
• CPC Class Codes: H01J 37/32449 Gas control, e.g. control of the gas flow
• CPC Class Codes: H01J 37/32899 Multiple chambers, e.g. cluster tools
• CPC Class Codes: H01L 21/32136 using plasmas
• CPC Class Codes: H01L 21/67069 for drying etching

Abstract

An exemplary system may include a chamber configured to contain a semiconductor substrate in a processing region of the chamber. The system may include a first remote plasma unit fluidly coupled with a first access of the chamber and configured to deliver a first precursor into the chamber through the first access. The system may still further include a second remote plasma unit fluidly coupled with a second access of the chamber and configured to deliver a second precursor into the chamber through the second access. The first and second access may be fluidly coupled with a mixing region of the chamber that is separate from and fluidly coupled with the processing region of the chamber. The mixing region may be configured to allow the first and second precursors to interact with each other externally from the processing region of the chamber.

Claims

1. A system for semiconductor processing, the system comprising:

a chamber configured to contain a semiconductor substrate in a processing region of the chamber, the chamber comprising a lid and sidewalls defining an internal volume of the chamber;

a first remote plasma unit fluidly coupled with a first access of the chamber defined through the lid and configured to deliver a first precursor into the chamber through the first access;

a second remote plasma unit fluidly coupled with a second access of the chamber separate from the first access, the second access defined through the lid and configured to deliver a second precursor into the chamber through the second access, wherein the first and second accesses of the chamber provide access to a mixing region in the internal volume of the chamber separate from and fluidly coupled with the processing region of the chamber, and wherein the mixing region is configured to allow the first and second precursors to interact with each other in the internal volume of the chamber and externally from the processing region of the chamber;

a showerhead postioned within the chamber and at least partially defining the mixing region from below, wherein the lid defines the mixing region from above;

a faceplate positioned within the chamber between the showerhead and the substrate processing region of the chamber, wherein the faceplate defines a plurality of apertures configured to allow the first precursor and the second percursor to flow from the mixing region towards the processing region;

an ion suppressor positioned within the chamber between the faceplate and the substrate processing region of the chamber, wherein the faceplate is electrically coupled with an RF source, wherein the ion suppressor is electrically grounded, and wherein the chamber is configured to generate a capacitively-coupled plasma between the faceplate and ion suppressor operating as the electrodes of the capacitively-coupled plasma; and

an annular dielectric insert positioned between and contacting the faceplate and the ion suppressor, wherein the annular dielectric insert electrically isolates the faceplate and ion suppressor from one another, wherein the showerhead, the faceplate, the ion suppressor, and the annular dielectric insert are coaxially aligned along an axis of the chamber and configured to at least partially define a flow passage along the axis of the chamber for the first and second precursors to flow from the mixing region to the processing region.

2. The system of claim 1, wherein the ion suppressor is configured to at least partially suppress the flow of ionic species directed toward the processing region of the chamber.

3. The system of claim 1, wherein the chamber further comprises a gas distribution assembly located within the chamber at a top portion of or above the processing region of the chamber and configured to deliver both the first and second precursors into the processing region of the chamber.

4. The system of claim 3, wherein the gas distribution assembly comprises an upper plate and a lower plate, wherein the upper and lower plates are coupled with one another to define a volume between the plates, wherein the coupling of the plates provides first fluid channels through the upper and lower plates and second fluid channels through the lower plate that are configured to provide fluid access from the volume through the lower plate, and wherein the first fluid channels are fluidly isolated from the volume between the plates and the second fluid channels.

5. The system of claim 4, wherein the volume is fluidly accessible through a side of the gas distribution assembly fluidly coupled with a third access in the chamber separate from the first and second accesses of the chamber.

6. The system of claim 3, wherein the ion suppressor is directly coupled with and contacting the gas distribution assembly at an exterior region of the ion suppressor.

7. The system of claim 1, wherein the first access and second access are coupled with a top portion of the chamber.

8. The system of claim 1, wherein the showerhead is configured to distribute the first and second precursors through the chamber.

9. The system of claim 8, wherein a dielectric spacer is positioned between the showerhead and the first remote plasma unit and the second remote plasma unit, and wherein the dielectric spacer at least partially defines the mixing region.

10. The system of claim 1, wherein the first remote plasma unit comprises a first material and the second remote plasma system comprises a second material.

11. The system of claim 10, wherein the first material is selected based on the composition of the first precursor, and wherein the second material is selected based on the composition of the second precursor.

12. The system of claim 11, wherein the first material and second material are different materials.

13. The system of claim 1, wherein the first remote plasma unit is configured to operate at a first power level that is selected based on the composition of the first precursor, and wherein the second remote plasma unit is configured to operate at a second power level that is selected based on the composition of the second precursor.

14. The system of claim 1, wherein the faceplate, ion suppressor, and the annular dielectric insert are stacked with one another to at least partially define sidewalls of the chamber.

15. The system of claim 1, wherein the ion suppressor includes a plurality of rings of apertures, wherein each ring is hexagonally shaped, and wherein each of the apertures of each ring is arranged at an equal distance from each adjacent apertures.

16. The system of claim 1, wherein the faceplate includes a plurality of apertures each configured to facilitate the flow of at least a portion of ions from the first precursor or the second precursor through the faceplate.

17. The system of claim 1, wherein the faceplate includes a plurality of apertures each configured with a tapered portion extending outward toward the processing region, and wherein the ion suppressor includes a plurality of apertures each configured with a tapered portion extending outward away from the processing region.

18. The system of claim 1, wherein the faceplate and the ion suppressor are configured to generate the capacitively-coupled plasma at a power level below or about 1 kW such that concentrations of radical species entering into the processing region are similar to concentrations of radical species entering into the mixing region from the first remote plasma unit and the second remote plasma unit.

19. The system of claim 1, wherein the showerhead includes a first plurality of apertures, wherein the faceplate includes a second plurality apertures, wherein the ion suppressor includes a third plurality of apertures, and wherein a density of the second plurality of apertures is less than a density of the first plurality of apertures and is less than a density of the third plurality of apertures.

20. The system of claim 1, wherein the coupling between the first remote plasma unit and the chamber and the coupling between the second remote plasma and the chamber are respectively configured such that a flow path for the first precursor to travel from the first remote plasma unit to the mixing region of the chamber is greater than a flow path for the second precursor to travel from the second remote plasma unit to the mixing region of the chamber, and wherein the flow paths are determined based at least in part on respective recombination rates of radicals from the first precursor and the second precursor.

21. A system for semiconductor processing, the system comprising:

a chamber configured to contain a semiconductor substrate in a processing region of the chamber, the chamber comprising a lid and sidewalls defining an internal volume of the chamber;

a first remote plasma unit fluidly coupled with a first access of the chamber defined through the lid and configured to deliver a first precursor into the chamber through the first access;

a second remote plasma unit fluidly coupled with a second access of the chamber separate from the first access, the second access defined through the lid and configured to deliver a second precursor into the chamber through the second access, wherein the first and second accesses of the chamber provide access to a mixing region in the internal volume of the chamber separate from and fluidly coupled with the processing region of the chamber, and wherein the mixing region is configured to allow the first and second precursors to interact with each other in the internal volume of the chamber and externally from the processing region of the chamber;

a showerhead positioned within the chamber to at least partially define the mixing region from below, wherein the lid defines the mixing region from above;

an annular insert positioned adjacent the showerhead and defining an exterior of the mixing region;

an ion suppressor positioned within the chamber between the showerhead and the substrate processing region of the chamber, wherein the ion suppressor comprises a plate defining apertures, and wherein the ion suppressor is configured to operate as an electrically grounded electrode for a capacitively-coupled plasma formable within the chamber;

an annular dielectric insert positioned between the ion suppressor and the showerhead, wherein the annular dielectric insert is in contact with the ion suppressor; and

a gas distribution assembly positioned between the ion suppressor and the processing region of the chamber, wherein the gas distribution assembly is in direct contact with the ion suppressor.

22. The system of claim 21, wherein the showerhead, the ion suppressor, the annular insert, the annular dielectric insert, and the gas distribution assembly are in a stacked arrangement, and each at least partially define sidewalls of the chamber.

23. A system for semiconductor processing, the system comprising:

a chamber configured to contain a semiconductor substrate in a processing region of the chamber, the chamber comprising a lid and sidewalls defining an internal volume of the chamber;

a first remote plasma unit fluidly coupled with a first access of the chamber defined through the lid and configured to deliver a first precursor into a mixing region of in the internal volume of the chamber, wherein the mixing region is separate from and fluidly coupled with the processing region of the chamber;

a second remote plasma unit fluidly coupled with a second access of the chamber separate from the first access, the second access defined through the lid and configured to deliver a second precursor into the mixing region in the internal volume of the chamber through the second access, wherein the mixing region is configured to allow the first and second precursors to interact with each other in the internal volume of the chamber and externally from the processing region of the chamber;

a first annular insert positioned downstream of and contacting the lid and configured to at least partially define the sidewalls;

a showerhead positioned downstream of and contacting the first annular insert, wherein the showerhead defines a plurality of apertures, and wherein the lid, the first annular insert, and the showerhead are configured to collectively define the mixing region;

a second annular insert positioned downstream of and contacting the showerhead and configured to at least partially define the sidewalls;

a faceplate positioned downstream of the showerhead and spaced apart from the showerhead by the second annular insert, wherein the faceplate defines a plurality of apertures;

a third annular insert positioned downstream of and contacting the faceplate and configured to at least partially define the sidewalls;

an ion suppressor positioned downstream of and contacting the third annular insert, wherein the ion suppressor defines a plurality of apertures, wherein the faceplate is electrically coupled with an RF source, wherein the ion suppressor is electrically grounded, wherein the third annular insert is configured to electrically isolate the faceplate and ion suppressor from one another, wherein the faceplate, the ion suppressor, and the third annular insert are configured to define a chamber plasma region, wherein the mixing region, the chamber plasma region, and the processing region are arranged along an axis of the chamber, wherein the faceplate and the ion suppressor are configured to operate as electrodes for generating a capacitively-coupled plasma within the chamber plasma region, wherein each of the plurality of apertures of the faceplate is configured with a tapered portion extending outward toward the chamber plasma region, and wherein each of the plurality of apertures of the ion suppressor is configured with a tapered portion extending outward toward the chamber plasma region;

a gas distribution assembly positioned downsteam of and contacting the ion suppressor, wherein the gas distribution assembly is configured to at least partially define the processing region, wherein the gas distribution assembly further includes an annular body configured to at least partially define the sidewalls, and wherein the showerhead, the second annular insert, the faceplate, the third annular insert, and the ion suppressor collectively define a flow passage along the axis of the chamber for the first and second precursors to flow from the mixing region to the processing region; and

a pedestal configured to support the semicondcutor substrate in the processing region, wherein the showerhead, the faceplate, the ion suppressor, and the gas distribution assembly, and the substrate support are coaxially aligned along the axis of the chamber.