Defective pixel compensation method
AssigneeMicronic Laser Systems AB
InventorTorbjörn Sandström
Life of this patent
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Abstract
The present invention relates to a method for compensating the impact of at least one defective pixel with a known position in a spatial light modulator (SLM) when creating a pattern of the SLM on a work piece covered with a layer sensitive to electromagnetic radiation. A source for emitting electromagnetic radiation is provided. Said radiation is illuminating said SLM having a plurality of modulating elements (pixels). In a writing pass an image of said modulator is projected on said work piece. A compensation for defective pixels in at least one other writing pass is performed. The invention also relates to an apparatus for performing said method.
Claims64
A method for compensating the impact of at least one defective pixel with a known position in at least one spatial light modulator (SLM) when creating a pattern of said at least one SLM on a work piece covered at least partly with a layer sensitive to electromagnetic radiation, comprising the actions of:
- providing a source for emitting electromagnetic radiation,
- illuminating by said radiation said at least one SLM having a plurality of modulating elements (pixels),
- projecting in a writing pass an image of said modulator on said work piece,
- performing a compensation for defective pixels in at least one other writing pass.
A method for compensating the impact of at least one defective pixel with a known position in at least one spatial light modulator (SLM) when creating a pattern of said at least one SLM on a work piece covered at least partly with a layer sensitive to electromagnetic radiation, comprising the actions of:
- providing a source to emit electromagnetic radiation,
- illuminating by said radiation said at least one SLM having a plurality of modulating elements (pixels),
- projecting an image of said at least one SLM on a detector arrangement to measure a dose of radiation
- performing a compensation of said defective pixel by at least one of the most adjacent pixels in said at least one SLM.
A method for compensating the impact of at least one defective pixel in at least one spatial light modulator (SLM) when creating a pattern of said at least one SLM on a work piece covered at least partially with a layer sensitive to electromagnetic radiation, comprising the action:
- setting the pixels in said at least one SLM in a predetermined state,
- illuminating by a radiation source said at least one SLM,
- projecting the image of said at least one SLM on a measuring device,
- measuring the dose of the pixels,
- identifying defective pixels,
- performing a compensation for said defective pixels in at least one writing pass by means of pixels in said at least one SLM other than said defective pixels.
A method for compensating the impact of at least one defective pixel with a known position in at least one spatial light modulator (SLM) when creating a pattern of said at least one SLM on a work piece covered at least partly with a layer sensitive to electromagnetic radiation, comprising the actions of:
- providing a source for emitting electromagnetic radiation,
- illuminating by said radiation said at least one SLM having a plurality of modulating elements (pixels),
- projecting in a first writing pass an image of said modulator on said work piece using a first set of pixels in said at least one SLM,
- performing a pre compensation of at least one defective pixel in at least one subsequent writing pass by at least one compensation pixel in at least one prior writing pass,
- projecting in at least a second writing pass said image of said modulator on said workpiece using at least a second set of pixels in said at least one SLM.
A method for compensating the impact of at least one defective pixel with a known position in at least one spatial light modulator (SLM) when creating a pattern of said at least one SLM on a work piece covered at least partly with a layer sensitive to electromagnetic radiation, comprising the actions of:
- providing a source for emitting electromagnetic radiation,
- illuminating by said radiation said at least one SLM having a plurality of modulating elements (pixels),
- projecting in a first writing pass an image of said modulator on said work piece using a first set of pixels in said at least one SLM,
- performing a post compensation of at least one defective pixel in at least one prior writing pass by at least one compensation pixel in at least one subsequent writing pass,
- projecting in at least a second writing pass said image of said modulator on said workpiece using at least a second set of pixels in said at least one SLM.
A method for compensating the impact of at least one defective pixel with a known position in at least one spatial light modulator (SLM) when creating a pattern of said at least one SLM on a work piece covered with a layer sensitive to electromagnetic radiation, comprising the actions of:
- fracturing and rendering the pattern to be printed,
- calculating exposure values for at least one SLM pixels,
- locating bad pixels,
- determine if said bad pixels are in a critical position,
- providing a source for emitting electromagnetic radiation,
- illuminating by said radiation said at least one SLM having a plurality of modulating elements pixels),
- compensating for bad pixels in critical positions.
An apparatus for compensating the impact of at least one defective pixel with a known position in at least one spatial light modulator (SLM) when creating a pattern of said at least one SLM on a work piece covered at least partly with a layer sensitive to electromagnetic radiation, comprising
- a source to emit electromagnetic radiation,
- a projection system to project in a first writing pass an image of said modulator on said work piece using a first set of pixels in said at least one SLM,
- at least one pixel in said at least one SLM in at least one prior writing pass to perform a pre compensation of defective pixels in at least one subsequent writing pass,
- a projection system to project in at least a second writing pass said image of said modulator on said workpiece using at least a second set of pixels in said at least one SLM,
- at least one pixel in said at least one SLM in at least one latter writing pass to perform a post compensation of defective pixels in at least one prior writing pass.
An apparatus for compensating the impact of at least one defective pixel with a known position in at least one spatial light modulator (SLM) when creating a pattern of said at least one SLM on a work piece covered at least partly with a layer sensitive to electromagnetic radiation, comprising a source for emitting electromagnetic radiation, a projection system for illuminating said at least one SLM, having a plurality of modulating elements (pixels), by said radiation and projecting in a writing pass an image of said modulator on said work piece, a detector arrangement (65) for measuring the dose of pixels from the image of said at least one SLM and a computer (66) for performing a compensation for defective pixels in at least one other writing pass out of said image on said detector (65).
An apparatus for compensating the impact of at least one defective pixel with a known position in at least one spatial light modulator (SLM) (30) when creating a pattern of said at least one SLM (30) on a work piece (60) covered at least partly with a layer sensitive to electromagnetic radiation, comprising a source for emitting electromagnetic radiation, a projection system for illuminating said SLM (30), having a plurality of modulating elements (pixels), by said radiation and projecting in a writing pass an image of said modulator (30) on said work piece (60), a detector arrangement (65) for measuring the dose of pixels from the image of said at least one SLM, and a computer (66) for performing a compensation for defective pixels (110) by using at least one of the most adjacent pixels (111, 112, 113, 114, 115, 116, 117, 118) to said defective pixel (110).
A method for detecting at least one defective pixel in at least one SLM, comprising the actions of
- addressing all pixels in said at least one SLM with a first steering signal,
- illuminating said at least one SLM with electromagnetic radiation,
- recording an image of said at least one SLM,
- computing a gradient field of the recorded image,
- computing a divergence of the gradient field,
- identifying extreme values from the computed divergence which corresponds to defective pixels.
A method for detecting at least one defective pixel in at least one SLM, comprising the actions of
- addressing all pixels in said at least one SLM with a first steering signal,
- illuminating said at least one SLM with electromagnetic radiation,
- recording a first image of said at least one SLM,
- addressing all pixels in said at least one SLM with a second steering signal,
- illuminating said at least one SLM with electromagnetic radiation,
- recording a second image of said at least one SLM,
- computing the difference between said first image and said second image,
- identifying bad pixels where the computed difference has a local minimum.
A method for detecting at least one defective pixel in at least one SLM, comprising the actions of
- addressing a pattern to said at least one SLM,
- illuminating said SLM with electromagnetic radiation,
- recording a first image of said at least one SLM,
- comparing said recorded image with pattern data at feature edges,
- identifying bad pixels where the feature edge is moved a predetermined distance.
Dependencies are inferred from the claim text.