Illumination system for AR metrology tool
AssigneeApplied Materials, Inc.
InventorsYangyang Sun, Jinxin Fu, Kazuya Daito, Ludovic Godet
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Abstract
Embodiments described herein provide for light engines of a measurement system and methods of using the light engines. The measurement system includes a light engine operable to illuminate a first grating of an optical device. The light engine projects a pattern with a light from a light engine. The light engine projects a pattern to the first grating such that a metrology metric may be extracted from one or more images captured by a detector of the measurement system. The metrology metrics are extracted by processing the image. The metrology metrics determine if the optical device meets image quality standards.
Claims19
A measurement system, comprising:
- a stage operable to retain an optical device or an optical device substrate having at least one optical device disposed thereon;
- a light engine disposed above the stage, the light engine including:
- one or more light sources operable to project a light to the optical device at a range of wavelengths;
- a reticle tray disposed below the one or more light sources, the reticle tray having a plurality of reticles disposed thereon, each reticle of the plurality of reticles having a different pattern to be projected when the light is directed to each reticle of the plurality of reticles;
- an alignment camera adjacent to the light engine, the alignment camera positioned to capture one or more images of one or more alignment markers on the optical device or the optical device substrate;
- and
- a reflection detector adjacent to the light engine, the reflection detector positioned to detect outcoupled beams projected from the at least one optical device.
A measurement system, comprising:
- a stage operable to retain an optical device or an optical device substrate having at least one optical device disposed thereon;
- and
- a light engine disposed above the stage, the light engine including:
- a plurality of light sources, the plurality of light sources operable to project a light to the optical device at a range of wavelengths;
- a first lens operable to collimate the light from each of the plurality of light sources;
- a reticle tray disposed below the plurality of light sources, the reticle tray having a plurality of reticles disposed thereon, each reticle of the plurality of reticles having a different pattern to be projected when the light is directed to each reticle of the plurality of reticles, each reticle pattern corresponding to a different metrology metric, the reticle tray movable such that each of the plurality of reticles is positionable below the first lens;
- and
- a second lens disposed below the reticle tray, the second lens operable to receive the pattern projected from each of the plurality of reticles and operable to project the different pattern to an input coupling grating of the optical device.
A method, comprising:
- projecting a first pattern with a light from a light engine, the light engine having a light source that projects the light at a range of wavelengths to a first reticle of a reticle tray disposed below the light source, the reticle tray having the first pattern that is projected to an optical device, the light engine disposed in a measurement system, the measurement system having:
- a stage disposed under the light engine;
- a tray disposed on the stage, the tray having the optical device or an optical device substrate having the optical device disposed thereon, the optical device receives the first pattern;
- and
- a reflection detector oriented toward the stage;
- detecting one or more images of the first pattern, the image detected when the pattern undergoing total internal reflection through the optical device is outcoupled to the reflection detector;
- processing the image to extract a first metrology metric;
- projecting a second pattern by projecting light from the light source to a second reticle having the second pattern different than the first pattern to the optical device;
- detecting one or more images of the second pattern;
- and
- processing the image to extract a second metrology metric.
Dependencies are inferred from the claim text.