Freeform optical substrates in waveguide displays
AssigneeApplied Materials, Inc.
InventorsDavid Sell, Samarth Bhargava
Life of this patent
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Abstract
Embodiments of the present disclosure generally relate to methods of forming a substrate having a target thickness distribution at one or more eyepiece areas across a substrate. The substrate includes eyepiece areas corresponding to areas where optical device eyepieces are to be formed on the substrate. Each eyepiece area includes a target thickness distribution. A base substrate thickness distribution of a base substrate is measured such that a target thickness change can be determined. The methods described herein are utilized along with the target thickness change to form a substrate with the target thickness distribution.
Claims19
An optical device, comprising:
- a base substrate, the base substrate having a base substrate thickness distribution;
- an index matching layer disposed over the base substrate, wherein the index matching layer and the base substrate have a target thickness distribution defined by a distance between a top surface of the index matching layer and a bottom surface of the base substrate, wherein the target thickness distribution is different than the base substrate thickness distribution;
- and
- a plurality of optical device structures formed in the index matching layer, wherein depths of at least two of the optical device structures in the index matching layer are different, the depths in the index matching layer corresponding to the target thickness distribution.
An optical device, comprising:
- a base substrate, wherein the base substrate has a target thickness distribution, the target thickness distribution defined by a distance between a top surface and a bottom surface of the base substrate;
- and
- a plurality of optical device structures formed in the base substrate, wherein depths of at least two of the optical device structures in the base substrate are different, the depths in the base substrate corresponding to the target thickness distribution, wherein the optical device is formed by:
- measuring a base substrate thickness distribution across the base substrate;
- determining a target thickness change, the target thickness change determined by subtracting the base substrate thickness distribution from the target thickness distribution;
- forming the target thickness distribution in the base substrate by disposing a resist over the base substrate and developing the resist utilizing a lithography process to form a gray-tone distribution having a thickness distribution corresponding to the target thickness distribution;
- and
- forming a plurality of optical device structures in the base substrate, wherein the plurality of optical device structures correspond to the target thickness distribution.
A substrate, comprising:
- a plurality of inactive areas;
- a plurality of eyepiece areas disposed between the plurality of inactive areas, wherein each eyepiece area includes a target thickness distribution across each of the plurality of eyepiece areas, the target thickness distribution defined by a distance between a top surface and a bottom surface of the substrate at each of the plurality of eyepiece areas;
- and
- an optical device formed at each of the plurality of eyepiece areas, each optical device having a plurality of optical device structures formed in the substrate or an index matching layer, wherein depths of at least two of the optical device structures in the substrate or index matching layer are different, the depths in the index matching layer corresponding to the target thickness distribution.
Dependencies are inferred from the claim text.