Wide bandgap semiconductor waveguide structures

• US 20040146264A1
• Filed: 01/28/2003
• Published: 07/29/2004
• Est. Priority Date: 06/16/2000
• Status: Active Grant

• Current Assignee: Wayne State University
• Original Assignee: Wayne State University
• Inventors: Safadi, Mona R., Auner, Gregory W.
• Granted Patent: US 7,043,129 B2
• Time in Patent Office: Days
• US Class Current: 385/130
• CPC Class Codes: A61N 5/0601 Apparatus for use inside the body
• CPC Class Codes: G02B 6/102 for infrared and ultraviolet radiation
• CPC Class Codes: G02B 6/12002 Three-dimensional structures
• CPC Class Codes: G02B 6/122 Basic optical elements, e.g. light-guiding paths
• CPC Class Codes: G02B 6/13 Integrated optical circuits characterised by the manufacturing method
• CPC Class Codes: G02B 6/136 by etching
• CPC Class Codes: G02B 6/30 for use between fibre and thin-film device

Abstract

A waveguide structure for transmitting broad spectrum light, includes a wide bandgap semiconductor thin film arranged on a substrate and ablated to form a waveguide channel to transmit the broad spectrum light.

Claims

1. A waveguide structure for transmitting broad spectrum light, comprising:

a wide bandgap semiconductor thin film arranged on a substrate and ablated to form a waveguide channel to transmit the broad spectrum light.

2. The waveguide structure of claim 1, wherein the broad spectrum light includes ultraviolet light and infrared light.

3. The waveguide structure of claim 1, wherein the broad spectrum light includes light with a range of 5 microns to 750 nanometers.

4. The waveguide structure of claim 1, wherein the wide bandgap semiconductor thin film includes aluminum nitride and the substrate includes sapphire.

5. The waveguide structure of claim 1, wherein the waveguide channel is approximately 5 μ

m to 50 μ

m wide.

6. The waveguide structure of claim 1, further comprising:

a termination hole for the light to exit the waveguide structure.

7. The waveguide structure of claim 6, further comprising:

a pixelated array of termination holes to direct the broad spectrum light.

8. A waveguide structure for transmitting broad spectrum light for use with a physiological delivery system, comprising:

a wide bandgap semiconductor thin film arranged on a substrate and ablated to form a waveguide channel to transmit the broad spectrum light;

wherein the waveguide structure is integrated with the physiological drug delivery system.

9. The waveguide structure of claim 8, wherein the physiological drug delivery system includes a microfluidic retinal prosthesis.

10. A waveguide structure for transmitting broad spectrum light for use with a miniaturized spectrometer system, comprising:

a wide bandgap semiconductor thin film arranged on a substrate and ablated to form a waveguide channel to transmit the broad spectrum light;

wherein the waveguide structure is arranged to transmit light to the miniaturized spectrometer system.

11. A method for fabricating a broad spectrum waveguide structure, the method comprising:

depositing a wide bandgap semiconductor thin film onto a substrate; and

micro-machining the deposited wide bandgap semiconductor thin film to form a waveguide channel.

12. The of claim 11, wherein the wide bandgap semiconductor thin film includes aluminum nitride and the substrate includes sapphire.

13. The method of claim 11, wherein the step of depositing the wide bandgap semiconductor thin film further includes:

cleaning ultrasonically the substrate using at least one of acetone and methanol;

etching the substrate in an acidic mixture;

pressuring an ultra high vacuum chamber of a plasma source molecular beam epitaxy system to a base vacuum pressure;

loading the substrate into the ultra-high vacuum chamber;

heating the substrate to a temperature of about 800°

C.;

operating an impeller of the plasma source beam epitaxy system to accelerate ions;

maintaining an energy level half that of a deposited crystal displacement energy;

maintaining a temperature of at least one of 400°

C. and 650°

C. during deposition; and

rotating the substrate at a temperature of 650°

C. for final growth of the wide bandgap semiconductor thin film.

14. The method of claim 13, wherein the base vacuum pressure is 1×

10<sup>−

10</sup> Torr, a supplied power is 200 Watts, a deposition pressure is 1×

10<sup>−

3</sup> Torr, and at least one of Nitrogen (N2) and Argon (AR) flow is 10;

40 sccm.

15. The method of claim 11, wherein the step of micro-machining the wide bandgap semiconductor thin film further includes:

arranging the wide bandgap semiconductor thin film on a scanning stage of an excimer laser micro-machining arrangement; and

ablating the wide bandgap semiconductor thin film at selective areas with laser energy pulses to form the waveguide channels.

16. The method of claim 15, wherein the wide bandgap semiconductor thin film is ablated with 300 to 1500 laser energy pulses having 194.4 mJ of energy.

17. The method of claim 15, wherein the wide bandgap semiconductor thin film is ablated with 1350 to 1875 laser energy pulses having 155.52 mJ of energy.

18. The method of claim 15, wherein the wide bandgap semiconductor thin film is ablated with 500 to 2500 laser energy pulses having 116.64 mJ of energy.

19. The method of claim 15, wherein the wide bandgap semiconductor thin film is ablated with 2250 to 3750 laser energy pulses having 77.76 mJ of energy.

20. The method of claim 15, wherein the wide bandgap semiconductor thin film is ablated with 1500 to 7500 laser energy pulses having 194.4 mJ of energy.

21. The method of claim 15, wherein the selective areas are approximately 15 microns wide and 2.5 μ

m deep.

22. The method of claim 15, wherein the laser energy pulses have a frequency of 5 Hz.