APPARATUS AND METHODS FOR MICROWAVE PROCESSING OF SEMICONDUCTOR SUBSTRATES

• US 20140038431A1
• Filed: 03/29/2012
• Published: 02/06/2014
• Est. Priority Date: 04/25/2011
• Status: Active Grant

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Stowell, Michael W., Foad, Majeed A., Hofmann, Ralf, Aderhold, Wolfgang R., Moffatt, Stephen
• Granted Patent: US 9,018,110 B2
• Time in Patent Office: Days
• US Class Current: 438/795
• CPC Class Codes: H01L 21/263 with high-energy radiation H01L21/261 takes precedence
• CPC Class Codes: H01L 21/324 Thermal treatment for modifying the properties of semiconductor bodies, e.g. annealing, sintering H01L21/20 - H01L21/288 and H01L21/302 - H01L21/322 take precedence
• CPC Class Codes: H01L 21/67115 mainly by radiation
• CPC Class Codes: H05B 6/702 using coaxial cables
• CPC Class Codes: H05B 6/708 in particular slotted waveguides

Abstract

Methods and apparatus for radiation processing of semiconductor substrates using microwave or millimeter wave energy are provided. The microwave or millimeter wave energy may have a frequency between about 600 MHz and about 1 THz. Alternating current from a magnetron is coupled to a leaky microwave emitter that has an inner conductor and an outer conductor, the outer conductor having openings with a dimension smaller than a wavelength of the emitted radiation. The inner and outer conductors are separated by an insulating material. Interference patterns produced by the microwave emissions may be uniformized by phase modulating the power to the emitter and/or by frequency modulating the frequency of the power itself. Power from a single generator may be divided to two or more emitters by a power divider.

Claims

1. A chamber for processing a semiconductor substrate, comprising:

a thermal energy source disposed in the chamber;

a microwave energy source disposed in the chamber; and

a substrate support disposed between the thermal energy source and the microwave energy source.

2. The chamber of claim 1, wherein the microwave energy source comprises a leaky coaxial antenna.

3. The chamber of claim 2, wherein the leaky coaxial antenna is a substantially planar phased array of connected leaky coaxial segments.

4. The chamber of claim 2, wherein the leaky coaxial antenna is curved or jointed.

5. The chamber of claim 2, further comprising a second coaxial antenna that is a passive antena or a leaky antenna.

6. The chamber of claim 1, further comprising a motor rotationally coupled to the microwave energy source.

7. The chamber of claim 2, wherein the leaky coaxial antenna comprises an inner conductor and a perforated outer conductor.

8. The chamber of claim 7, wherein the perforations are elongated slots with ends that are rectangular or rounded, and each slot has an axial dimension and a transverse dimension, and the transverse dimension is larger than the axial dimension.

9. The chamber of claim 7, wherein the perforations have an axial dimension that is less than half the wavelength of the microwave radiation produced by the leaky coaxial microwave source.

10. A microwave source for a semiconductor processing chamber, comprising:

a conductive core having a longitudinal axis;

a dielectric coating over the conductive core;

an outer conductor around the dielectric coating, the outer conductor having a plurality of openings oriented along the longitudinal axis.

11. The microwave source of claim 10, further comprising a housing disposed around the outer conductor, wherein the housing is formed from a material resistant to deposition and etching.

12. A method of processing a semiconductor substrate, comprising:

disposing the substrate on a substrate support in a chamber having a plasma-free microwave source and a thermal energy source;

rapidly heating the substrate to a temperature of about 1,100°

C. or less using the thermal energy source; and

applying a pulse of microwave energy having power density of about 2 W/cm² or less to the substrate.

13. The method of claim 12, further comprising rotating the substrate while delivering a plurality of pulses of microwave energy.

14. The method of claim 13, wherein the applying the pulse of microwave energy is performed over a time of about 1 msec or less.

15. A method of processing a semiconductor substrate, comprising:

disposing the substrate on a substrate support in a chamber having a leaky coaxial microwave source disposed in the chamber;

generating standing wave microwave energy by powering a magnetron coupled to the leaky coaxial microwave source; and

varying the standing wave microwave energy by varying a characteristic of the leaky coaxial microwave source, the magnetron, or the chamber.

16. The method of claim 15, wherein the magnetron frequency is varied by coupling a waveform generator to the magnetron.

17. The method of claim 15, wherein the microwave energy has average power density less than about 2 W/cm² and peak intensity variation less than about 5%.

18. The method of claim 17, wherein the leaky coaxial microwave source is a linear source, and the substrate and the linear source move respectively to translate the microwave energy across the substrate in a direction transverse to the longitudinal direction of the linear source.

19. The method of claim 15, wherein the varying a characteristic of the leaky coaxial microwave source or the magnetron comprises varying the magnetron frequency or phase.

20. A method of processing a semiconductor substrate, comprising:

disposing the substrate in a processing chamber;

exposing the substrate to pulsed microwave radiation from a plurality of microwave radiation sources disposed in a planar arrangement in the processing chamber; and

rotating the substrate.

21. The method of claim 20, further comprising phase modulating the microwave radiation at a frequency that is not an integer multiple of the substrate rotation frequency.

22. The method of claim 21, further comprising pulsing the microwave energy at a frequency that is not an integer multiple of either the substrate rotation frequency or the phase modulation frequency.