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US RE44,116 E1Granted
Substrate-alignment using detector of substrate material
AssigneeUltratech, Inc.
InventorsEmily True, Ray Ellis, Shiyu Zhang
Life of this patent
Estimating the term…
Abstract
Methods and apparatuses are provided for positioning a substrate having a target that may be located on either the front-side or the backside of the substrate. The optical detector that views the target contains a signal-generating material that is substantially identical to the substrate material.
Claims65
A method for positioning a substrate, comprising:
- (a) holding a substrate having a first surface and a reflective feature at a position that is separated from the first surface by a first layer of material having at least partial transparency to light of a selected wavelength;
- (b) directing light of the selected wavelength toward the reflective feature;
- and
- (c) using an optical image detector to intercept light reflected by the feature to generate a sufficiently analyzable image signal to allow a signal-analyzing system to recognize and to locate the position of the reflective feature with a degree of precision sufficient for substrate alignment,
- wherein the optical image detector comprises a signal-generating material that is substantially identical in composition to the first layer material.
2 more elements
An apparatus for positioning a substrate, comprising:
- a substrate having a first surface and a reflective feature at a position that is separated from the first surface by a first layer of material having at least partial transparency to light of a selected wavelength;
- a substrate holder holding the substrate;
- a light source for generating light of the selected wavelength, wherein the light source is positioned to direct light of the selected wavelength to the reflective feature;
- an optical image detector positioned to intercept light reflected by the reflective feature, wherein the image detector comprises a signal-generating material that is substantially identical in composition to the first layer material of the first layer and is capable of generating an image signal from the intercepted light;
- and
- a machine vision system in signal-receiving relation to the image detector, wherein the machine vision system is capable of analyzing the image signal to recognize the reflective feature and to determine the position of the reflective feature with a sufficient degree of precision.
3 more elements
A method for positioning a substrate, comprising:
- (a) holding a substrate having a first surface and a feature at a position that is separated from the first surface by a first layer of material, wherein the material of the first layer has at least partial transparency to light of a selected wavelength and the feature has a transparency different from that of the material of the first layer;
- (b) directing light of the selected wavelength through the substrate;
- and
- (c) using an optical image detector to intercept light transmitted through the substrate to generate a sufficiently analyzable image signal to allow a signal-analyzing system to recognize and locate the position of the reflective feature with a degree of precision sufficient for substrate alignment,
- wherein the optical image detector comprises a signal-generating material that is substantially identical in composition to the material of the first layer.
2 more elements
A method for positioning a substrate, comprising:
- (a) holding a substrate having a first surface and a reflective feature at a position that is separated from the first surface by a first layer of material having at least partial transparency to light of a selected wavelength;
- (b) directing light of the selected wavelength toward the reflective feature;
- and
- (c) using an optical image detector to intercept light reflected by the feature to generate a sufficiently analyzable image signal to allow a signal-analyzing system to recognize and to locate the position of the reflective feature with a degree of precision sufficient for substrate alignment,
- wherein the optical image detector comprises a signal-generating material that has a signal to noise ratio of at least 3:1.
2 more elements
An apparatus for positioning a substrate, comprising:
- a substrate having a first surface and a reflective feature at a position that is separated from the first surface by a first layer of material having at least partial transparency to light of a selected wavelength;
- a substrate holder holding the substrate;
- a light source for generating light of the selected wavelength, wherein the light source is positioned to direct light of the selected wavelength to the reflective feature;
- an optical image detector positioned to intercept light reflected by the reflective feature, wherein the image detector comprises a signal-generating material that has a signal to noise ratio of at least 3:1 and is capable of generating an image signal from the intercepted light;
- and
- a machine vision system in signal-receiving relation to the image detector,
- wherein the machine vision system is capable of analyzing the image signal to recognize the reflective feature and to determine the position of the reflective feature with a sufficient degree of precision.
4 more elements
A method for positioning a substrate, comprising:
- (a) holding a substrate having a first surface and a feature at a position that is separated from the first surface by a first layer of material, wherein the material of the first layer has at least partial transparency to light of a selected wavelength and the feature has a transparency different from that of the material of the first layer;
- (b) directing light of the selected wavelength through the substrate;
- and
- (c) using an optical image detector to intercept light transmitted through the substrate to generate a sufficiently analyzable image signal to allow a signal-analyzing system to recognize and locate the position of the reflective feature with a degree of precision sufficient for substrate alignment,
- wherein the optical image detector comprises a signal-generating material that has a composition that is different from the material of the first layer.
2 more elements
Dependencies are inferred from the claim text.