System and method for providing residual stress test structures
First Claim
1. A test unit configured to indicate residual stress in a deposited film, wherein the test unit is configured to interferometrically modulate light indicative of average residual stress in two orthogonal directions of the film.
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Accused Products
Abstract
The invention comprises systems and methods determining residual stress such as that found in interferometric modulators. In one example, a test unit can be configured to indicate residual stress in a film by interferometrically modulating light indicative of an average residual stress in two orthogonal directions of the substrate. The test unit can include a reflective membrane attached to the substrate where membrane is configured as a parallelogram with at least a portion of each side attached to the substrate, and an interferometric cavity formed between a portion of the membrane and a portion of the substrate, and where the membrane is configured to deform based on the residual stress of in the film and modulate light indicative of the amount of membrane deformation.
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Citations
39 Claims
- 1. A test unit configured to indicate residual stress in a deposited film, wherein the test unit is configured to interferometrically modulate light indicative of average residual stress in two orthogonal directions of the film.
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6. A system configured to determine residual stress of a deposited film, comprising:
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one or more test units, each test unit comprising a reflective membrane that comprises a portion of the deposited film, wherein the membrane is configured as a parallelogram with at least a portion of each side attached to a substrate, wherein the membrane is configured to deform based on the residual stress of the film and modulate light indicative of the amount of membrane deformation; an imaging system positionable to receive modulated light reflecting from the one or more test units and configured to produce image data associated with the received light; and a computer in communication with the imaging system, the computer configured to process the image data and generate information relating to the residual stress in the film. - View Dependent Claims (7, 8, 9, 10, 11, 12, 13)
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- 14. A method of measuring residual stress of a deposited film, the method comprising interferometrically modulating light using a membrane that deforms based on residual stress of the film such that the modulated light indicates the residual stress in the film in two orthogonal directions.
- 20. A test unit for measuring residual stress in a deposited film, comprising means for reflecting a first portion of light, and means for reflecting a second portion of light that interferes with the first portion of light to modulate light indicative of average residual stress in two orthogonal directions of the film.
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27. A method of manufacturing a device to indicate the residual stress in a deposited film, the method comprising disposing a thin reflective membrane on a substrate such that an interferometric cavity is formed between a portion of the membrane and a portion of the substrate, wherein the membrane comprises a portion of the deposited film, and wherein the membrane is configured in the shape of a parallelogram with at least a portion of each side attached to the substrate, and the membrane is further configured to deform based on the residual stress of the film in two orthogonal directions and modulate light indicative of the amount of deformation.
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28. A display device, comprising:
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a substrate; one or more one bi-stable display elements disposed on the substrate wherein each the one or more bi-stable display elements comprise a moveable membrane which comprises a portion of a film; and one or more test units, each test unit comprising a membrane defining a portion of an interferometric cavity, wherein the membrane comprises a portion of the film having at least three perimeter edges, at least a portion of each of the three perimeter edges being attached to the substrate, wherein the one or more test units are configured to modulate light such that the modulated light is indicative of the residual stress of the film. - View Dependent Claims (29, 30, 31, 32, 33, 34, 35, 36)
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37. A method of determining residual stress of a film layer incorporated in a display, comprising:
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interferometrically modulating light, wherein the modulated light is indicative of the residual stress in the film layer in two orthogonal directions; detecting the modulated light; generating image data associated with the detected modulated light; and determining residual stress of the film layer of the display based on the image data. - View Dependent Claims (38, 39)
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Specification