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Author

Kenji Saitoh

Bio: Kenji Saitoh is an academic researcher from Canon Inc.. The author has contributed to research in topics: Diffraction & Diffraction grating. The author has an hindex of 19, co-authored 95 publications receiving 1454 citations.


Papers
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Patent
24 Apr 2002
TL;DR: In this paper, an exposure method that includes the steps of forming a phase shift mask having a desired pattern and a cyclic dummy pattern overlaid onto the desired pattern is provided.
Abstract: There is provided an exposure method that includes the steps of forming a phase shift mask having a desired pattern and a cyclic dummy pattern overlaid onto the desired pattern, a part of the desired pattern to be resolved by effects of the dummy pattern being thicker than the dummy pattern's line width, illuminating the phase shift mask by using illumination light having a peak near or on an optical axis in an intensity distribution to transfer the desired pattern onto the exposure plane by projecting light having passed through the phase shift mask onto the exposure plane.

222 citations

Patent
20 Sep 2002
TL;DR: In this article, a method for setting a mask pattern and an illumination condition suitable for an exposure method for using plural kinds of light to illuminate a mask that arranges a predetermined pattern and a smaller auxiliary pattern, so as to resolve the predetermined pattern without resolving the auxiliary pattern on a target via a projection optical system.
Abstract: A method for setting a mask pattern and an illumination condition suitable for an exposure method for using plural kinds of light to illuminate a mask that arranges a predetermined pattern and an auxiliary pattern smaller than the predetermined pattern, so as to resolve the predetermined pattern without resolving the auxiliary pattern on a target via a projection optical system includes the steps of forming data for the predetermined pattern, forming data for the auxiliary pattern, and setting the illumination condition for defining an effective light source of illumination using the plural kinds of light.

73 citations

Patent
18 Feb 1992
TL;DR: In this article, a position detecting system for detecting the position of a substrate having a surface, with respect to a first direction perpendicular to the surface of the substrate and a second direction parallel to the first direction, by use of a mark formed on a substrate and having an optical power, is disclosed.
Abstract: A position detecting system, for detecting the position of a substrate having a surface, with respect to a first direction perpendicular to the surface of the substrate and a second direction perpendicular to the first direction, by use of a mark formed on the substrate and having an optical power, is disclosed. The system includes a directing device for directing a radiation beam to the mark so that the radiation beam is deflected by the mark; a sensor for receiving the radiation beam deflected by the mark, wherein the position of the radiation beam incident on the sensor is shiftable in a third direction in accordance with the position of the substrate with respect to the first direction and also is shiftable in a fourth direction, different from the third direction, in accordance with the position of the substrate with respect to the second direction; and a detecting device for detecting the position of the substrate with respect to the first and second directions on the basis of an output of the sensor corresponding to the position of incidence of the radiation beam upon the sensor.

69 citations

Patent
22 Jan 1996
TL;DR: In this article, an encoder includes an electrically conductive reference scale having surface steps formed at predetermined positions, an electric conductive probe having a tip disposed opposed to the reference scale, where the probe is relatively movable in a direction different from the opposing direction of the tip of the probe and the scale.
Abstract: An encoder includes an electrically conductive reference scale having surface steps formed at predetermined positions; an electrically conductive probe having a tip disposed opposed to the reference scale; wherein the reference scale and the probe are relatively movable in a direction different from the opposing direction of the tip of the probe and the reference scale; a portion for applying an electrical voltage to between the reference scale and the probe; a portion for detecting a change in a tunnel current between the reference scale and the probe, to between which the electric voltage is applied by the voltage applying portion at the time of the relative movement between the scale and the probe, the detecting portion detecting the change in the tunnel current when the probe passes a position opposed to a surface step of the reference scale; and portion for detecting the amount of the relative movement between the scale and probe, on the basis of the detection by the change detecting portion.

66 citations

Proceedings ArticleDOI
26 Jul 1999
TL;DR: In this article, a new exposure technology IDEAL is proposed to realize the benefit of these new technologies in practice, in which first exposure is for fine patterns, which are imaged with high contrast and large depth of focus, while second exposure is done with multileveled light distribution.
Abstract: The pursuit of ultimate resolution by optical lithography has given rise to many new technologies, such as PSM, oblique illumination etc. In order to realize the benefit of these new technologies in practice, a new exposure technology IDEAL is proposed. First exposure is for fine patterns, which are imaged with high contrast and large depth of focus, while second exposure is done with multileveled light distribution. These two exposures collaborate each other to form fine patterns with reasonable focus margin and good 2D profile. Experimental result of logic gate patterns are shown and demonstrate the possibility of k 1 equals 0.3 lithography. Using IDEAL, KrF lithography can be extended to 100-110 nm and ArF to 80 nm resolution.

63 citations


Cited by
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Patent
20 May 2009
TL;DR: In this paper, the system and methods for implementing array cameras configured to perform super-resolution processing to generate higher resolution super-resolved images using a plurality of captured images and lens stack arrays that can be utilized in array cameras are disclosed.
Abstract: Systems and methods for implementing array cameras configured to perform super- resolution processing to generate higher resolution super-resolved images using a plurality of captured images and lens stack arrays that can be utilized in array cameras are disclosed. Lens stack arrays in accordance with many embodiments of the invention include lens elements formed on substrates separated by spacers, where the lens elements, substrates and spacers are configured to form a plurality of optical channels, at least one aperture located within each optical channel, at least one spectral filter located within each optical channel, where each spectral filter is configured to pass a specific spectral band of light, and light blocking materials located within the lens stack array to optically isolate the optical channels.

594 citations

Book
24 May 2019
TL;DR: The second edition of this book as discussed by the authors was written to address several needs, and the revisions for the second edition were made with those original objectives in mind, and many new topics have been included in this text commensurate with the progress that has taken place during the past few years, and several subjects are discussed in more detail.
Abstract: Lithography is a field in which advances proceed at a swift pace. This book was written to address several needs, and the revisions for the second edition were made with those original objectives in mind. Many new topics have been included in this text commensurate with the progress that has taken place during the past few years, and several subjects are discussed in more detail. This book is intended to serve as an introduction to the science of microlithography for people who are unfamiliar with the subject. Topics directly related to the tools used to manufacture integrated circuits are addressed in depth, including such topics as overlay, the stages of exposure, tools, and light sources. This text also contains numerous references for students who want to investigate particular topics in more detail, and they provide the experienced lithographer with lists of references by topic as well. It is expected that the reader of this book will have a foundation in basic physics and chemistry. No topics will require knowledge of mathematics beyond elementary calculus.

508 citations

Patent
28 Jan 2008
TL;DR: In this article, a lithographic apparatus configured to project a patterned beam of radiation onto a target portion of a substrate is described, which includes a first radiation dose detector and a second radiation dose detectors, each detector comprising a secondary electron emission surface configured to receive a radiation flux and to emit secondary electrons due to the receipt of the radiation flux.
Abstract: A lithographic apparatus configured to project a patterned beam of radiation onto a target portion of a substrate is disclosed. The apparatus includes a first radiation dose detector and a second radiation dose detector, each detector comprising a secondary electron emission surface configured to receive a radiation flux and to emit secondary electrons due to the receipt of the radiation flux, the first radiation dose detector located upstream with respect to the second radiation dose detector viewed with respect to a direction of radiation transmission, and a meter, connected to each detector, to detect a current or voltage resulting from the secondary electron emission from the respective electron emission surface.

451 citations

Patent
08 Oct 2008
TL;DR: In this article, the annulus of an intervertebral disc is treated with an expandable treatment device which is deployed at least partially in the subannular space, which helps to secure the treatment device in place.
Abstract: The present invention provides methods and devices for treating the annulus of an intervertebral disc. The methods and devices can employ an expandable treatment device which is deployed at least partially in the subannular space. Fixation devices and methods are also disclosed, which help to secure the treatment device in place.

417 citations

Patent
11 Jul 2002
TL;DR: In this article, a template is brought into contact with the liquid and the cured liquid includes an imprint of any patterns formed in the template, and the remainder of the substrate is imprinted by moving the template to a different portion of the template and repeating the imprint lithography process.
Abstract: The present invention is directed to methods for patterning a substrate by imprint lithography. Imprint lithography is a process in which a liquid is dispensed onto a substrate. A template is brought into contact with the liquid and the liquid is cured. The cured liquid includes an imprint of any patterns formed in the template. In one embodiment, the imprint process is designed to imprint only a portion of the substrate. The remainder of the substrate is imprinted by moving the template to a different portion of the template and repeating the imprint lithography process.

352 citations