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Kenneth W. Nill

Bio: Kenneth W. Nill is an academic researcher. The author has contributed to research in topics: Copper interconnect & Achromatic lens. The author has an hindex of 4, co-authored 5 publications receiving 159 citations.

Papers
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Patent
06 Jul 2007
TL;DR: The CD-GISAXS as discussed by the authors achieves reduced measurement times by increasing throughput using longer wavelength radiation such as x-rays in reflective geometry to increase both the collimation acceptance angle of the incident beams and the scattering signal strength, resulting in a substantial combined throughput gain.
Abstract: CD-GISAXS achieves reduced measurement times by increasing throughput using longer wavelength radiation (˜12×, for example) such as x-rays in reflective geometry to increase both the collimation acceptance angle of the incident beams and the scattering signal strength, resulting in a substantial combined throughput gain. This wavelength selection and geometry can result in a dramatic reduction in measurement time. Furthermore, the capabilities of the CD-GISAXS can be extended to meet many of the metrology needs of future generations of semiconductor manufacturing and nanostructure characterization, for example.

59 citations

Patent
08 Jul 2005
TL;DR: In this paper, a system for performing inspection and metrology operations on metallization processes such as on back-end-of-line (BEOL) thickness and step coverage is described.
Abstract: Systems and methods for performing inspection and metrology operations on metallization processes such as on back-end-of-line (BEOL) metallization thickness and step coverage are disclosed. Specific examples include measurements of thickness and uniformity of barrier layers, including tantalum for example, and seed layers, including copper for example, in Damascene, including dual-Damascene, trenches during the interconnect fabrication steps of integrated circuit production. The invention also relates to the detection and measurement of void formation during and after copper electroplating. The invention utilizes x-ray fluorescence to measure the absolute thicknesses and the thickness uniformity of the barrier layers in the trenches, the copper seed layers for electroplating, and the final copper interconnects.

57 citations

Patent
05 Nov 2002
TL;DR: In this article, a Fresnel zone plate and a refractive lens are combined to solve the high chromatic aberration problem of zone plates, allowing the use of short wavelength radiation in the 1-15 nm spectral range.
Abstract: A lithography apparatus having achromatic Fresnel objective (AFO) that combines a Fresnel zone plate and a refractive Fresnel lens. The zone plate provides high resolution for imaging and focusing, while the refractive lens takes advantage of the refraction index change properties of appropriate elements near absorption edges to recombine the electromagnetic radiation of different energies dispersed by the zone plate. This compound lens effectively solves the high chromatic aberration problem of zone plates. The lithography apparatus allows the use of short wavelength radiation in the 1-15 nm spectral range to print high resolution features as small as 20 nm.

39 citations

Patent
08 Jul 2005
TL;DR: In this paper, a system for performing inspection and metrology operations on metallization processes such as on back-end-of-line (BEOL) thickness and step coverage is described.
Abstract: Systems and methods for performing inspection and metrology operations on metallization processes such as on back-end-of-line (BEOL) metallization thickness and step coverage are disclosed. Specific examples include measurements of thickness and uniformity of barrier layers, including tantalum for example, and seed layers, including copper for example, in Damascene, including dual-Damascene, trenches during the interconnect fabrication steps of integrated circuit production. The invention also relates to the detection and measurement of void formation during and after copper electroplating. The invention utilizes x-ray fluorescence to measure the absolute thicknesses and the thickness uniformity of the barrier layers in the trenches, the copper seed layers for electroplating, and the final copper interconnects.

4 citations

Patent
05 Nov 2002
TL;DR: In this paper, a Fresnel zone plate and a refractive lens are combined to solve the high chromatic aberration problem of zone plates, allowing the use of short wavelength radiation in the 1-15 nm spectral range.
Abstract: A lithography apparatus having achromatic Fresnel objective (AFO) that combines a Fresnel zone plate and a refractive Fresnel lens. The zone plate provides high resolution for imaging and focusing, while the refractive lens takes advantage of the refraction index change properties of appropriate elements near absorption edges to recombine the electromagnetic radiation of different energies dispersed by the zone plate. This compound lens effectively solves the high chromatic aberration problem of zone plates. The lithography apparatus allows the use of short wavelength radiation in the 1-15 nm spectral range to print high resolution features as small as 20 nm.

Cited by
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Patent
Calle Hellestam1
05 Aug 2014
TL;DR: In this article, a method for forming a 3D article through successive fusion of locations of a powder bed is proposed, where locations with a shorter scan length than the maximum scan length are provided with a time sink before and/or after a scan line so that the time period between each two adjacent scan lines is constant.
Abstract: The invention relates to a method for forming a three-dimensional article through successive fusion of locations of a powder bed. The method comprising: providing a model of said three-dimensional article; applying a powder layer on a work table; determining a maximum scan length of an energy beam; directing said energy beam from a first energy beam source over said work table with constant energy causing said first powder layer to fuse in first selected locations according to said model to form a first cross section of said three-dimensional article, wherein locations with a shorter scan length than said maximum scan length is provided with a time sink before and/or after said scan line so that the time period between each two adjacent scan lines is constant throughout the manufacture of said three-dimensional article.

111 citations

Patent
Ulf Ackelid1
31 Mar 2014
TL;DR: In this article, the authors provide a method and apparatus for forming a three-dimensional article through successive fusion of parts of at least one layer of a powder bed provided on a work table in an additive manufacturing machine.
Abstract: Various embodiments provide a method and apparatus for forming a three-dimensional article through successive fusion of parts of at least one layer of a powder bed provided on a work table in an additive manufacturing machine, which parts corresponds to successive cross sections of the three-dimensional article. The method comprises the steps of: applying a layer of predetermined thickness of powder particles on the work table, applying a coating on at least a portion of the powder particles, which coating is at least partially covering the powder particles, and fusing the powder particles on the work table with an electron beam.

88 citations

Patent
Ulric Ljungblad1
15 Jul 2009
TL;DR: In this paper, a method for producing 3D objects using a powdery material which can be solidified by irradiating it with a high-energy beam is described, which is characterized in that the method comprises the step of determining a rate at which the temperature of the second layer (8) increases after application onto the first layer.
Abstract: The invention concerns a method for producing three-dimensional objects (6) layer by layer using a powdery material (7) which can be solidified by irradiating it with a high-energy beam(4), said method comprising the steps of: applying a first layer of powdery material onto a working area (5); solidifying a part of said first layer by irradiating it with a high-energy beam; andapplying a second layer (8) of powdery material onto thefirst, partly solidified layer. The invention is characterized in that the method comprises the step of: determining a rate at which the temperature of the second layer (8) increases after application onto the first layer.The invention also concerns an apparatus configured to operate according tothe above method.

80 citations

Patent
Ulric Ljungblad1, Martin Wildheim1
18 Nov 2013
TL;DR: In this paper, the authors proposed a method for forming a three-dimensional article comprising the steps of: providing a predetermined amount of powder for forming the first powder layer on a start plate, distributing said predetermined amount with a powder distributor for forming said powder layer, and directing an energy beam over the start plate causing said first layer to fuse in selected locations according to a model to form a first cross section of the article.
Abstract: A method for forming a three-dimensional article, said method comprising the steps of: providing a predetermined amount of powder for forming a first powder layer on a start plate, distributing said predetermined amount of powder with a powder distributor for forming said first powder layer, directing an energy beam over said start plate causing said first powder layer to fuse in selected locations according to a model to form a first cross section of said three-dimensional article. At least one image of the powder to be distributed is captured with a camera at least one time during said distribution of said powder on said start plate for forming said first powder layer and at least one value of at least one parameter in said image detected with said camera is compared with a reference parameter value.

79 citations

Patent
Ulric Ljungblad1
04 Apr 2014
TL;DR: In this article, a method for successive fusion of parts of a powder bed comprising of a first powder layer on a work table, directing an energy beam over the work table causing the second powder layer to fuse in selected locations according to the model to form a first cross section of the 3D article, where the second layer is bonded to the first layer.
Abstract: A method for forming a three-dimensional article through successive fusion of parts of a powder bed comprising: providing a model of the three dimensional article, applying a first powder layer on a work table, directing an energy beam over the work table causing the first powder layer to fuse in selected locations according to the model to form a first cross section of the three-dimensional article, applying a second powder layer on the work table, directing the energy beam over the work table causing the second powder layer to fuse in selected locations according to the model to form a second cross section of the three-dimensional article, wherein the second layer is bonded to the first layer, detecting a local thickness in at least two positions in at least the second powder layer, varying an energy beam parameter depending on the detected local thickness of the second powder layer.

78 citations