SYSTEM, METHOD AND APPARATUS FOR CONTROLLING ION ENERGY DISTRIBUTION

• US 20110259851A1
• Filed: 08/29/2010
• Published: 10/27/2011
• Est. Priority Date: 04/26/2010
• Status: Active Grant

• Current Assignee: AES Global Holdings Pte Ltd. (Advanced Energy Industries, Inc. (China))
• Original Assignee: Advanced Energy Industries Incorporated
• Inventors: Hoffman, Daniel J., Heckman, Randy, Brouk, Victor
• Granted Patent: US 9,287,086 B2
• Time in Patent Office: Days
• US Class Current: 216/61
• CPC Class Codes: C23C 14/345 using substrate bias
• CPC Class Codes: C23C 16/50 using electric discharges generation and control of plasma in discharge tubes for surface treatment H01J37/32, H01J37/34
• CPC Class Codes: H01J 37/24 Circuit arrangements not adapted to a particular application of the tube and not otherwise provided for
• CPC Class Codes: H01J 37/32009 Arrangements for generation of plasma specially adapted for examination or treatment of objects, e.g. plasma sources plasma generation in general H05H1/24
• CPC Class Codes: H01J 37/32082 Radio frequency generated discharge H01J37/32357, H01J37/32366, H01J37/32394 and H01J37/32403 take precedence
• CPC Class Codes: H01J 37/32174 Circuits specially adapted for controlling the RF discharge
• CPC Class Codes: H01J 37/32935 Monitoring and controlling tubes by information coming from the object and/or discharge
• CPC Class Codes: H01J 37/3299 Feedback systems

Abstract

Systems, methods and apparatus for regulating ion energies in a plasma chamber are disclosed. An exemplary method includes placing a substrate in a plasma chamber, forming a plasma in the plasma chamber, controllably switching power to the substrate so as to apply a periodic voltage function to the substrate, and modulating, over multiple cycles of the periodic voltage function, the periodic voltage function responsive to a desired distribution of energies of ions at the surface of the substrate so as to effectuate the desired distribution of ion energies on a time-averaged basis.

Claims

1. A system for plasma-based processing, comprising:

a plasma processing chamber configured to contain a plasma;

a substrate support positioned within the plasma processing chamber and disposed to support a substrate,

an ion-energy control portion, the ion-energy control portion provides at least one ion-energy control signal responsive to at least one ion-energy distribution setting that is indicative of a desired distribution ion energy distribution at the surface of the substrate;

a switch-mode power supply coupled to the substrate support and the ion-energy control portion, the switch-mode power supply including one or more switching components configured to apply power to the substrate responsive to the ion-energy control signal so as to effectuate the desired ion energy distribution at the surface of the substrate; and

an ion current compensation component coupled to the substrate support, the ion current compensation component effecting controllable width of the ion energy distribution.

2. The system of claim 1, wherein the switch-mode power supply is DC-coupled to the substrate support.

3. The system of claim 1 wherein the ion current compensation component is configured to enable a user to define a spread of a uniform distribution of ion energy.

4. The system of claim 1, wherein the substrate support includes an electrostatic chuck, the system including an electrostatic chuck supply coupled to the electrostatic chuck.

5. The system of claim 1, including an additional power supply coupled to the substrate support, the additional power supply is adapted to apply power to the substrate support so as to sustain the plasma in the plasma processing chamber.

6. The system of claim 1, wherein the switch-mode power supply is also adapted to apply power to the substrate support to ignite and sustain the plasma in the plasma processing chamber.

7. The system of claim 1, wherein the switch-mode power supply is configured to apply a periodic voltage function to the substrate support responsive to the one or more drive signals;

wherein the ion-energy control portion is configured to modulate, over multiple cycles of the periodic voltage function, at least one parameter of the periodic voltage function responsive to the at least one ion-energy distribution setting so as to generate the desired distribution of energies of ions at the surface of the substrate on a time-averaged basis.

8. The system of claim 7, wherein the at least one parameter includes a voltage amplitude.

9. An apparatus for plasma-based processing, comprising:

a controller configured to provide one or more drive-control signals;

a switch-mode power supply an output disposed to couple to a substrate support, the switch-mode power supply including one or more switching components configured to apply a periodic voltage function to the output responsive to the one or more drive signals; and

an ion-energy control portion, the ion-energy control portion modulating, over multiple cycles of the periodic voltage function, at least one parameter of the periodic voltage function responsive to at least one ion-energy distribution setting that is indicative of a desired ion energy distribution at the surface of the substrate.

10. The apparatus of claim 9, wherein the ion energy control portion includes a memory that includes data that defines a plurality of ion energy distribution functions, the ion-energy control portion modulating, based upon data corresponding to a selected one of the ion energy distribution functions, the periodic voltage function so as to effectuate the desired distribution of energies of ions at the surface of the substrate on a time-averaged basis.

11. The apparatus of claim 9 including:

a user interface, the user interface enabling the user to select values for parameters that define the desired distribution of energies of ions, on a time-averaged basis, at the surface of the substrate;

wherein the ion-energy control portion includes a custom IEDF component that converts the parameters to modulation data, the ion-energy control portion modulating the periodic voltage function using the modulation data so as to effectuate the desired distribution of energies of ions at the surface of the substrate on a time-averaged basis.

12. The apparatus of claim 9, including:

an ion current compensation component coupled to the output, the ion current compensation component compensating for ion current in the plasma.

13. A method for plasma-based processing, comprising:

placing a substrate in a plasma chamber;

forming a plasma in the plasma chamber;

controllably switching power to the substrate so as to apply a periodic voltage function to the substrate; and

modulating, over multiple cycles of the periodic voltage function, the periodic voltage function responsive to a desired ion energy distribution at the surface of the substrate so as to effectuate the desired ion energy distribution on a time-averaged basis.

14. The method of claim 13 wherein modulating the periodic voltage function includes modulating an amplitude of the periodic voltage function.

15. The method of claim 13 including:

obtaining values of parameters that define the desired distribution of energies of ions at the surface of the substrate;

converting the obtained parameter values to modulation data; and

modulating the periodic voltage function using the modulation data.

16. The method of claim 15, wherein the values of parameters are obtained from an operator managing the plasma-based processing.

17. The method of claim 13 including:

selecting the desired distribution of ion energies from a memory including data that defines a plurality of ion energy distribution functions so as to select a particular ion energy distribution function; and

modulating the periodic voltage function so as to effectuate the particular ion energy distribution function on a time-averaged basis.

18. The method of claim 13, including applying the controllably switched power to the substrate support to ignite and sustain the plasma in the plasma processing chamber.

19. The method of claim 13, including:

controlling an ion compensation current so as to enable control of a spread of uniform ion energies at the surface of the substrate on a time-averaged basis.

20. A method for plasma-based processing, comprising:

placing a substrate in a plasma chamber;

forming a plasma in the plasma chamber;

receiving at least one ion-energy distribution setting that is indicative of one or more ion energies at a surface of the substrate; and

controllably switching power to the substrate so as to effectuate a desired distribution of ion energies on a time-averaged basis; and

compensating for ion current in the plasma so as to effect a desired width of the desired ion energy distribution.

21. The method of claim 20, wherein controllably switching power includes:

modulating over multiple cycles of a periodic voltage function, the periodic voltage function responsive to the at least one ion-energy distribution setting that is indicative of one or more ion energies at the surface of the substrate so as to effectuate the desired distribution of ion energies on a time averaged basis.

22. The method of claim 21, wherein receiving at least one ion-energy setting includes receiving data defining an ion energy distribution function.