Ultra-Fast Beam Dithering with Surface Acoustic Wave Modulator

• US 20080025354A1
• Filed: 07/31/2006
• Published: 01/31/2008
• Est. Priority Date: 07/31/2006
• Status: Abandoned Application

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Jennings, Dean
• Application Number:
  US11/461,397
• Publication Number:
  US 20080025354A1
• Time in Patent Office: Days
• US Class Current: 372/30
• CPC Class Codes: G02F 1/11 based on acousto-optical elements, e.g. using variable diffraction by sound or like mechanical waves acousto-optical deflection G02F1/33

Abstract

A method for processing a coherent light pulse is provided. A coherent light pulse is dithered at a high frequency when it is reflected off of or transmitted through a piezoelectric material having an optical interface surface. A SAW-producing device that is disposed on the piezoelectric material generates a surface acoustic wave (SAW) on the optical interface surface. A travelling SAW or a standing SAW may be generated on the optical interface surface.

Claims

1. A method of processing a pulse of coherent light, comprising:

providing a piezoelectric material having an optical interface surface;

producing a SAW on the optical interface surface, the SAW having a first fundamental frequency;

generating a pulse of coherent light; and

directing the pulse of coherent light onto the optical interface surface to produce a modulated light pulse, wherein the period of the fundamental frequency is less than the duration of the pulse of coherent light.

2. The method of claim 1, wherein the modulated light pulse produces non-coherent illumination when time-averaged over the duration of the light pulse.

3. The method of claim 1, wherein generating a pulse of coherent light comprises generating a pulse of coherent light having a duration of less than about 10 microseconds.

4. The method of claim 1, wherein generating a pulse of coherent light comprises generating a pulse of coherent light having an energy content of at least about 0.1 J/cm².

5. The method of claim 1, wherein directing the pulse of coherent light onto the optical interface surface comprises reflecting the pulse of coherent light off of the optical interface surface.

6. The method of claim 1, wherein directing the pulse of coherent light onto the optical interface surface comprises transmitting the pulse of coherent light through the optical interface surface.

7. The method of claim 1, wherein the first fundamental frequency is at least about 1 MHz.

8. The method of claim 1, further comprising producing a second SAW on the optical interface surface, the second SAW having a second fundamental frequency that differs from the first fundamental frequency by at least about 3%.

9. The method of claim 1, wherein generating a pulse of coherent light comprises generating a pulse of coherent light having a wavelength between about 10 nm and about 1,000 μ

m.

10. A method of thermally processing a substrate, comprising:

providing a piezoelectric material having an optical interface surface;

producing a SAW on the optical interface surface, the SAW having a fundamental frequency;

generating a pulse of coherent light;

directing the pulse of coherent light onto the optical interface surface to produce a modulated light pulse, wherein the period of the fundamental frequency is less than the duration of the pulse of coherent light; and

directing the non-coherent light pulse on a region of a substrate surface to thermally process a layer on a substrate.

11. The method of claim 10, wherein generating the pulse of coherent light further comprises:

generating a light pulse having an energy content of at least about 0.1 J/cm².

12. The method of claim 10, wherein generating the pulse of coherent light further comprises:

generating a pulse of coherent light having a duration of less than about 10 microseconds.

13. The method of claim 10 further comprising:

providing relative motion between the pulse of coherent light and the substrate.

14. A method of thermally processing a substrate, comprising:

producing a SAW;

generating a pulse of coherent light having an energy content of at least about 0.1 J/cm²;

modulating the pulse of coherent light using the SAW; and

thermally processing a region of a substrate surface with the modulated light pulse.

15. The method of claim 14, wherein generating the pulse of coherent light further comprises:

generating a pulse of coherent light having a duration of less than about 10 microseconds.

16. The method of claim 14 further comprising:

providing relative motion between the modulated pulse of light and the substrate.

17. The method of claim 14, wherein generating a pulse of coherent light comprises:

generating a pulse of coherent light having a wavelength between about 10 nm and about 1,000 μ

m.

18. The method of claim 14, wherein producing a SAW comprises:

producing a SAW on a piezoelectric material.