Methods and apparatus for waveguide metrology

Patent metadata

Field	Value
Publication number	US-11029206-B2
Application number	US-201916670976-A
Country	US
Kind code	B2
Filing date	Oct 31, 2019
Priority date	Nov 7, 2018
Publication date	Jun 8, 2021
Grant date	Jun 8, 2021

Abstract

Embodiments described herein relate to apparatus for measuring and characterizing performance of augmented and virtual reality waveguide structures utilizing glass substrates. The waveguide performance measuring systems generally include a light source configured to direct light towards an incoupling grating area on waveguide and one or more light detectors configured to collect light from an outcoupling grating area on a second side of the waveguide. The light source and one or more light detectors are disposed on one or more adjustable stages positioned about the waveguide. In certain embodiments, the one or more adjustable stages are configured to move in a linear fashion or revolve and/or rotate around the waveguide in an orbital motion.

First claim

What is claimed is:

1. A waveguide metrology system, comprising:
a light source coupled to a first stage and configured to direct light towards a sample waveguide holder disposed on a second stage, the light source disposed on a first side of the second stage;
one or more scanning detectors coupled to a third stage on a second side of the second stage opposite the first side, the one or more scanning detectors configured to collect light transmitted in a first direction from the sample waveguide holder towards the second side;
a reflection detector coupled to a fourth stage on the first side of the second stage, the reflection detector configured to collect light reflected in a second direction from the sample waveguide holder towards the first side; and
a spectrometer in communication with the one or more scanning detectors, wherein the system is configured to measure reflective and transmissive light diffraction efficiency characteristics of a sample waveguide in the sample waveguide holder.

2. The metrology system of claim 1 , wherein the first stage is configured to move linearly about an x, y, or z axis.

3. The metrology system of claim 1 , wherein the first stage is further configured to revolve up to about 180° around the second stage separate from any rotation by the second stage.

4. The metrology system of claim 1 , wherein the second stage is configured to rotate about a vertical axis.

5. The metrology system of claim 1 , further comprising:
a reflection detector disposed on the first stage adjacent to the light source.

6. A waveguide metrology system, comprising:
a light source coupled to a movable first stage and configured to transmit light towards a sample waveguide holder disposed on a second stage, the light source disposed on a first side of the second stage;
one or more scatterometers coupled to a movable third stage on a second side of the second stage opposite the first side, the third stage separately movable from the first stage, the one or more scatterometers configured to collect light transmitted in a first direction from the sample waveguide holder towards the second side;
one or more reflection detectors coupled to a movable fourth stage on the first side of the second stage, the fourth stage separately movable from the first stage and the third stage, the reflection detectors configured to collect light reflected in a second direction of from the sample waveguide holder towards the first side; and
a spectrometer in communication with the one or more scatterometers and the one or more reflection detectors, wherein the system is configured to measure reflective and transmissive light diffraction efficiency characteristics of a sample waveguide in the sample waveguide holder.

7. The metrology system of claim 6 , wherein the first stage is configured to move linearly about an x, y, and z axis.

8. The metrology system of claim 7 , wherein the first stage is further configured to revolve up to about 180° around the sample waveguide holder separate from any rotation by the second stage.

9. The metrology system of claim 6 , wherein the second stage is configured to move linearly about an x, y, and z axis.

10. The metrology system of claim 9 , wherein the second stage is further configured to rotate about the z axis.

11. The metrology system of claim 6 , wherein the third stage and the fourth stage are configured to revolve up to about 180° around the sample waveguide holder separate from any rotation by the second stage.

12. The metrology system of claim 6 , wherein the first stage and the second stage are synchronized to measure angular and spatial uniformity characteristics of a sample waveguide.

13. The metrology system of claim 6 , wherein the system is configured to measure field of view and light coupling efficiency characteristics of a sample waveguide.

14. The metrology system of claim 6 , wherein the system is configured to measure color uniformity characteristics of a sample waveguide.

15. The metrology system of claim 6 , where in the light source is a light engine and the system is configured to measure image resolution and contrast characteristics of a sample waveguide.

16. A waveguide metrology system, comprising:
a collimated light source coupled to a first movable stage;
a sample waveguide holder disposed on a second movable stage;
a reflection detector coupled to a third movable stage on a first side of the sample waveguide holder and configured to collect light reflected in a first direction from the sample waveguide holder;
a transmission detector coupled to a fourth movable stage on a second side of the sample waveguide holder and configured to collect light transmitted in a second direction from the sample waveguide holder, wherein the first stage, the third stage, and the fourth stage are configured to revolve up to about 180° around the sample waveguide holder separate from any rotation by the second stage; and
a spectrometer in communication with the reflection detector and the transmission detector, wherein the system is configured to measure reflective and transmissive light diffraction efficiency characteristics of a sample waveguide in the sample waveguide holder.

17. The metrology system of claim 16 , wherein the first stage and the second stage are configured to move linearly about an x, y, and z axis and rotate about the z axis.

18. The metrology system of claim 16 , wherein the third stage and the fourth stage are configured to move linearly about an x, y, and z axis.

19. The metrology system of claim 16 , wherein the light source comprises a white light source, a laser, or a light emitting diode.

Assignees

• Applied Materials Inc

Inventors

• Fu Jinxin
• Meyer Timmerman Thijssen Rutger
• Godet Ludovic

Classifications

• G01M11/04

  Optical benches therefor · CPC title

• G01M11/0285

  by measuring material or chromatic transmission properties (G01M11/0292 takes precedence) · CPC title

• G01M11/0278

  Detecting defects of the object to be tested, e.g. scratches or dust (investigating the presence of flaws or contamination on materials by optical means G01N21/88) · CPC title

• G01M11/0242

  by measuring geometrical properties or aberrations · CPC title

• G01M11/0214

  Details of devices holding the object to be tested · CPC title