LASER BASED PROCESSING OF LAYERED MATERIALS

• US 20120156875A1
• Filed: 09/16/2011
• Published: 06/21/2012
• Est. Priority Date: 09/16/2010
• Status: Active Grant

• Current Assignee: Rayd LLC
• Original Assignee: Rayd LLC
• Inventors: Srinivas, Ramanujapuram A., Greenberg, Michael, Gaudiosi, David, Mielke, Michael, Booth, Tim
• Granted Patent: US 9,114,482 B2
• Time in Patent Office: Days
• US Class Current: 438/675
• CPC Class Codes: B23K 2103/172 wherein at least one of the layers is non-metallic
• CPC Class Codes: B23K 26/36 Removing material B23K26/55, B23K26/57 take precedence
• CPC Class Codes: B23K 26/40 taking account of the properties of the material involved

Abstract

Systems and methods for laser based processing of layered materials. Methods may include selectively adjusting ultrafast laser output of an ultrafast laser device based upon one or more physical attributes of a layer of the layered material, applying the ultrafast laser output of the ultrafast laser device to the layer of the layered material along a tool path to ablate the layer along the tool path, and then re-executing the steps to ablate one or more additional layers, the re-execution occurring for each distinct layer of the layered material that is to be ablated.

Claims

1. A method for selectively ablating one or more layers of a layered material, the method comprising:

(a) selectively adjusting ultrafast laser output of an ultrafast laser device based upon one or more physical attributes of a layer of the layered material;

(b) applying the ultrafast laser output of the ultrafast laser device to the layer of the layered material along a tool path to ablate the layer along the tool path;

(c) re-executing steps (a) and (b) to ablate one or more additional layers, the re-execution of steps (a) and (b) occurring for each distinct layer of the layered material that is to be ablated; and

the selective ablation of the layered material prepares the layered material for subsequent processing.

2. The method according to claim 1, further comprising determining the physical attributes of a layer that is to be ablated before step (a).

3. The method according to claim 1, wherein the layered material includes a base layer, one or more device layers layered upon the base layer, and a getter layer covering an uppermost device layer of the one or more device layers.

4. The method according to claim 3, wherein the getter layer is comprised of any of a metallic alloy and a polymer.

5. The method according to claim 3, wherein the base layer includes any of an organic and an inorganic material.

6. The method according to claim 3, wherein subsequent processing includes any of dry etching, wet etching, plasma etching, cleaving, optical lithography, cleaning, texturing, and combinations thereof.

7. The method according to claim 1, wherein selectively adjusting ultrafast laser output includes any selectively adjusting one or more of pattern, pulse width, pulse energy level, focal point, frequency, laser repetition rate, fill spacing, number of passes, and combinations thereof, for the ultrafast laser device.

8. The method according to claim 7, wherein the pulse width is selected from any of a femtosecond, a picosecond, nanosecond, and combinations thereof.

9. The method according to claim 1, wherein applying ultrafast laser output to an additional layer occurs substantially simultaneously relative to the step of applying ultrafast laser output to a getter layer, the additional layer being disposed below an ablated portion of the getter layer.

10. A system for selectively ablating one or more layers of a layered material, the system comprising:

an ultrafast laser device comprising;

a laser emitting assembly for generating selectively adjustable ultrafast laser output;

a beam delivery assembly for delivering the selectively adjustable ultrafast laser output to the one or more layers of the layered material;

the ultrafast laser device is communicatively coupled with a processor, the processor executing instructions selectively adjusting the ultrafast laser output, the instructions comprising;

a control module that;

selectively adjusts the ultrafast laser output of the ultrafast laser device by selectively adjusting at least one of the laser generating assembly and the beam delivery assembly, based upon one or more physical attributes of a layer of the layered material received from an analysis module;

applies the ultrafast laser output of the ultrafast laser device to the layer of the layered material along a tool path to ablate the layer along the tool path; and

the selective ablation of the layered material prepares the layered material for subsequent processing.

11. The system according to claim 10, wherein the analysis module determines the physical attributes of a layer that is to be ablated before the control module applies the ultrafast laser output of the ultrafast laser device to the layer.

12. The system according to claim 10, wherein subsequent processing includes any of dry etching, wet etching, plasma etching, doping, implantation, deposition, cleaving, optical lithography, cleaning, texturing, and combinations thereof.

13. The system according to claim 10, wherein the control module selectively adjusts the ultrafast laser output by selectively adjusting any of pattern, pulse width, pulse energy level, frequency, laser repetition rate, fill spacing, number of passes, and combinations thereof.

14. The system according to claim 10, wherein the control system selectively adjusts a focal point of the ultrafast laser device by selectively modifying optical properties of the beam delivery assembly.

15. The system according to claim 13, wherein the pulse width is selected from any of a femtosecond, a picosecond, nanosecond, and combinations thereof.

16. The system according to claim 10, wherein the control module applies ultrafast laser output to an additional layer substantially simultaneously to the application of ultrafast laser output to a getter layer, the additional layer being disposed below an ablated portion of the getter layer.

17. A method for preparing a layered material for subsequent processing, the layered material including a getter layer disposed on an outer surface of the layer material, the method comprising:

selectively adjusting ultrafast laser output of an ultrafast laser device based upon one or more physical attributes of the getter layer; and

applying the ultrafast laser output of the ultrafast laser device to the getter layer according to a pattern to ablate the getter layer and expose a device layer positioned below the getter layer.

18. The method according to claim 17, further comprising determining the physical attributes of the getter layer, before the step of selectively adjusting the ultrafast laser output of the ultrafast laser device.

19. A method for processing a semiconductor wafer, the wafer having a base layer, one or more device layers, and a getter layer, the method comprising:

applying ultrafast laser output of an ultrafast laser to remove at least a portion of the getter layer from the semiconductor wafer; and

selectively applying ultrafast laser output of the ultrafast laser to at least one of the one or more device layers to ablate at least a portion of the at least one device layer to create a device structure therein.

20. The method according to claim 19, further comprising filling the device structure with any of a deposited material, an electrical device, an insulator, and combinations thereof.