NANOGRATING METHOD AND APPARATUS

• US 20180059297A1
• Filed: 08/22/2017
• Published: 03/01/2018
• Est. Priority Date: 08/22/2016
• Status: Active Grant

• Current Assignee: Magic Leap, Inc.
• Original Assignee: Magic Leap, Inc.
• Inventors: Peroz, Christophe, Melli, Mauro, Singh, Vikramjit, Jurbergs, David, Schmulen, Jeffrey Dean, Wang, Zongxing, Yang, Shuqiang, Xu, Frank Y., Luo, Kang, Menezes, Marlon Edward, Miller, Michael Nevin
• Granted Patent: US 10,481,317 B2
• Time in Patent Office: Days
• CPC Class Codes: G02B 2027/0114 comprising dichroic elements
• CPC Class Codes: G02B 2027/0118 comprising devices for improving the contrast of the display / brillance control visibility
• CPC Class Codes: G02B 2027/012 comprising devices for attenuating parasitic image effects
• CPC Class Codes: G02B 2027/0125 Field-of-view increase by wavefront division
• CPC Class Codes: G02B 2027/014 comprising information/image processing systems
• CPC Class Codes: G02B 2027/0174 holographic
• CPC Class Codes: G02B 2027/0178 Eyeglass type eyeglass details G02C
• CPC Class Codes: G02B 27/0018 with means for preventing ghost images anti-reflection coatings G02B1/11
• CPC Class Codes: G02B 27/0081 with means for altering, e.g. enlarging, the entrance or exit pupil
• CPC Class Codes: G02B 27/017 Head mounted
• CPC Class Codes: G02B 27/0172 characterised by optical features
• CPC Class Codes: G02B 27/0176 characterised by mechanical features
• CPC Class Codes: G02B 27/1086 operating by diffraction only
• CPC Class Codes: G02B 27/283 used for beam splitting or combining
• CPC Class Codes: G02B 27/30 Collimators
• CPC Class Codes: G02B 5/1823 in an overlapping or superposed manner
• CPC Class Codes: G02B 5/1857 using exposure or etching means, e.g. holography, photolithography, exposure to electron or ion beams
• CPC Class Codes: G02B 5/1866 Transmission gratings characterised by their structure, e.g. step profile, contours of substrate or grooves, pitch variations, materials G02B5/1809, G02B5/1828, G02B5/1833, G02B5/1838 and G02B5/1847 take precedence
• CPC Class Codes: G02B 5/1871 Transmissive phase gratings
• CPC Class Codes: G02B 5/3025 Polarisers, i.e. arrangements capable of producing a definite output polarisation state from an unpolarised input state G02B5/3008, G02B5/3016 take precedence
• CPC Class Codes: G02B 6/0016 : Grooves, prisms, gratings, scattering particles or rough surfaces
• CPC Class Codes: G02B 6/0023 : provided by one optical element, or plurality thereof, placed between the light guide and the light source, or around the light source
• CPC Class Codes: G02B 6/0035 : provided on the surface of the light guide or in the bulk of it
• CPC Class Codes: G02B 6/0036 : 2-D arrangement of prisms, protrusions, indentations or roughened surfaces
• CPC Class Codes: G02B 6/0038 : Linear indentations or grooves, e.g. arc-shaped grooves or meandering grooves, extending over the full length or width of the light guide
• CPC Class Codes: G02B 6/005 : provided by one optical element, or plurality thereof, placed on the light output side of the light guide
• CPC Class Codes: G02B 6/0076 : Stacked arrangements of multiple light guides of the same or different cross-sectional area
• CPC Class Codes: G02B 6/29325 : of the slab or planar or plate like form, i.e. confinement in a single transverse dimension only integrated circuit planar waveguide arrangements G02B6/12007; specially adapted for lighting G02B6/0011
• CPC Class Codes: G02B 6/34 : utilising prism or grating G02B6/293 takes precedence
• CPC Class Codes: G02B 7/008 : with means for compensating for changes in temperature or for controlling the temperature; thermal stabilisation
• CPC Class Codes: G02C 11/10 : Electronic devices other than hearing aids
• CPC Class Codes: G02C 5/16 : resilient or with resilient parts
• CPC Class Codes: G06F 1/163 : Wearable computers, e.g. on a belt
• CPC Class Codes: G06F 1/203 : for portable computers, e.g. for laptops
• CPC Class Codes: G06F 1/206 : comprising thermal management
• CPC Class Codes: G06F 3/011 : Arrangements for interaction with the human body, e.g. for user immersion in virtual reality blind teaching G09B21/00
• CPC Class Codes: G06F 3/013 : Eye tracking input arrangements G06F3/015 takes precedence
• CPC Class Codes: G06F 3/147 : using display panels
• CPC Class Codes: G09G 2320/0233 : Improving the luminance or brightness uniformity across the screen
• CPC Class Codes: G09G 2330/045 : Protection against panel overheating
• CPC Class Codes: G09G 2340/0464 : Positioning
• CPC Class Codes: G09G 3/001 : using specific devices not provided for in groups G09G3/02 - G09G3/36, e.g. using an intermediate record carrier such as a film slide; Projection systems; Display of non-alphanumerical information, solely or in combination with alphanumerical information, e.g. digital display on projected diapositive as background slide projectors per se G03B23/00 = 42 HP
• CPC Class Codes: G09G 3/002 : to project the image of a two-dimensional display, such as an array of light emitting or modulating elements or a CRT
• CPC Class Codes: G09G 3/2003 : Display of colours specific for liquid crystal displays G09G3/3607
• CPC Class Codes: G09G 3/2044 : using dithering
• CPC Class Codes: H04N 9/3102 : using two-dimensional electronic spatial light modulators micromechanical modulators as such G02B26/0833; liquid crystal modulators as such G02F1/13
• CPC Class Codes: H04N 9/3144 : Cooling systems cooling of liquid crystal cells in general G02F1/133382; cooling of projectors not peculiar to the presence of an electronic spatial light modulator G03B21/16
• CPC Class Codes: H04N 9/3164 : using multiple light sources
• CPC Class Codes: H05K 7/20963 : Heat transfer by conduction from internal heat source to heat radiating structure H05K7/20972 takes precedence

Abstract

A method of manufacturing a waveguide having a combination of a binary grating structure and a blazed grating structure includes cutting a substrate off-axis, depositing a first layer on the substrate, and depositing a resist layer on the first layer. The resist layer includes a pattern. The method also includes etching the first layer in the pattern using the resist layer as a mask. The pattern includes a first region and a second region. The method further includes creating the binary grating structure in the substrate in the second region and creating the blazed grating structure in the substrate in the first region.

Claims

1. A method of manufacturing a waveguide having a combination of a binary grating structure and a blazed grating structure, the method comprising:

cutting a substrate off-axis;

depositing a first layer on the substrate;

depositing a resist layer on the first layer, wherein the resist layer includes a pattern;

etching the first layer in the pattern using the resist layer as a mask, wherein the pattern includes a first region and a second region;

removing the resist layer;

coating a first polymer layer in the first region of the pattern;

etching the substrate in the second region of the pattern, creating the binary grating structure in the substrate in the second region;

removing the first polymer layer;

coating a second polymer layer in the second region of the pattern;

etching the substrate in the first region of the pattern, creating the blazed grating structure in the substrate in the first region;

removing the second polymer layer; and

removing the first layer from the substrate.

2. The method of claim 1, wherein the substrate comprises silicon.

3. The method of claim 1, wherein the first layer comprises silicon dioxide.

4. The method of claim 1, wherein the resist layer is deposited using lithography.

5. The method of claim 1, wherein etching the substrate in the second region of the pattern includes dry etching the substrate.

6. The method of claim 1, further comprising:

depositing a metal layer on the second polymer layer in the second region of the pattern.

7. The method of claim 6, wherein the metal layer comprises titanium.

8. The method of claim 6, wherein the metal layer is deposited using physical vapor deposition.

9. The method of claim 6, further comprising:

removing the metal layer after etching the substrate in the first region of the pattern.

10. The method of claim 1, wherein etching the substrate in the first region of the pattern comprises wet etching the substrate in the first region of the pattern.

11. The method of claim 10, wherein the substrate is wet etched using potassium hydroxide.

12. The method of claim 1, further comprising:

trimming the blazed grating structure in the substrate in the first region.

13. A method of manufacturing a waveguide having a multi-level binary grating structure, the method comprising:

coating a first etch stop layer on a first substrate;

adding a second substrate on the first etch stop layer;

depositing a first resist layer on the second substrate, wherein the first resist layer includes at least one first opening;

depositing a second etch stop layer on the second substrate in the at least one first opening;

removing the first resist layer from the second substrate;

adding a third substrate on the second substrate and the second etch stop layer;

depositing a second resist layer on the third substrate, wherein the second resist layer includes at least one second opening;

depositing a third etch stop layer on the third substrate in the at least one second opening;

removing the second resist layer from the third substrate;

etching the second substrate and the third substrate, leaving the first substrate, the first etch stop layer, the second etch stop layer and the second substrate in the at least one first opening, and the third etch stop layer and the third substrate in the at least one second opening; and

etching an exposed portion of the first etch stop layer, an exposed portion of the second etch stop layer, and the third etch stop layer, forming the multi-level binary grating.

14. The method of claim 13, wherein the first substrate comprises silicon or quartz.

15. The method of claim 13, wherein the second substrate and the third substrate comprise at least one of silicon, silicon dioxide, and silicon nitride.

16. The method of claim 13, wherein at least one of the first resist layer and the second resist layer is removed by lift off.

17. The method of claim 13, wherein at least one of the first resist layer and the second resist layer is removed by etching.

18. The method of claim 13, wherein at least one of the first resist layer and the second resist layer is removed by dissolving.

19. A method of manipulating light by an eyepiece layer, the method comprising:

receiving light from a light source at an input coupling grating having a first grating structure characterized by a first set of grating parameters;

receiving light from the input coupling grating at an expansion grating having a second grating structure characterized by a second set of grating parameters; and

receiving light from the expansion grating at an output coupling grating having a third grating structure characterized by a third set of grating parameters,

wherein at least one of the first grating structure, the second grating structure, or the third grating structure has a duty cycle that is graded.

20. The method of claim 19 wherein the duty cycle increases from a first surface that receives the light to a second surface that outputs the light.