Phase shifting and optical proximity corrections to improve CD control on logic devices in manufacturing for sub-0.35-μm i-line
07 Jul 1997-Vol. 3051, pp 146-153
TL;DR: In this paper, differential modification techniques were used to reduce the effects of topography, density, and low k lens issues in I-Line exposure wavelength for manufacturing at and beyond 0.35 micrometers.
Abstract: The use of I-Line exposure wavelength for manufacturing at and beyond 0.35 micrometers presents many challenges in manufacturing. The lack of resolution, depth of focus, exposure latitude, and iso/dense offsets have caused some to switch from I-Line to DUV. With our installed I-Line base we felt it necessary to implement techniques to extend our tool life, reduce manufacturing costs while improving manufacturing margins. The results of the differential modification techniques were used to reduce the effects of topography, density, and low k lens issues. The differences seen between the binary and phase shift plates show the advantage of phase shifting below 0.35 (mu) manufacturing. We have been able to demonstrate between critical dimension (CD) control using phase shift mask with dense iso compensation over a standard binary reticle. The data shows improved CD control across the stepper field, wafer, and overall lot distribution. The impact of this work was improved speed performance. It also allowed us to move the CD's to smaller dimension because of the better control without increasing fallout due to electrical parametric roll-off.
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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•
18 Sep 1997TL;DR: In this article, the phase shift mask and the single phase structure mask are derived from a set of masks used in a larger minimum dimension process technology and used for shrinking integrated circuit designs.
Abstract: A method and apparatus for creating a phase shifting mask and a structure mask for shrinking integrated circuit designs. One embodiment of the invention includes using a two mask process. The first mask is a phase shift mask and the second mask is a single phase structure mask. The phase shift mask primarily defines regions requiring phase shifting. The single phase structure mask primarily defines regions not requiring phase shifting. The single phase structure mask also prevents the erasure of the phase shifting regions and prevents the creation of undesirable artifact regions that would otherwise be created by the phase shift mask. Both masks are derived from a set of masks used in a larger minimum dimension process technology.
347 citations
Patent•
06 Feb 2002
TL;DR: In this paper, techniques for extending the use of phase shift techniques to implementation of masks used for complex layouts in the layers of integrated circuits, beyond selected critical dimension features, are presented.
Abstract: Techniques are provided for extending the use of phase shift techniques to implementation of masks used for complex layouts in the layers of integrated circuits, beyond selected critical dimension features. The method includes identifying features for which phase shifting can be applied, automatically mapping the phase shifting regions for implementation of such features, resolving phase conflicts which might occur according to a given design rule, and application of assist features and proximity correction features. The method includes applying an adjustment to a phase shift mask pattern including a first and a second phase shift window, and a control chrome with a control width, and/or to a trim mask pattern having a trim shape with a trim width based upon one or both of a rule based correction and a model based correction to improve a match between a resulting exposure pattern and a target feature.
241 citations
Patent•
02 Aug 2000
TL;DR: In this article, a shape can be defined by a set of associated edges in a specified configuration, and a catalog of shapes is defined and layout processing actions are associated with the various shapes.
Abstract: Layout processing can be applied to an integrated circuit (IC) layout using a shape-based system. A shape can be defined by a set of associated edges in a specified configuration. A catalog of shapes is defined and layout processing actions are associated with the various shapes. Each layout processing action applies a specified layout modification to its associated shape. A shape-based rule system advantageously enables efficient formulation and precise application of layout modifications. Shapes/actions can be provided as defaults, can be retrieved from a remote source, or can be defined by the user. The layout processing actions can be compiled in a bias table. The bias table can include both rule-based and model-based actions, and can also include single-edge shapes for completeness. The scanning of the IC layout can be performed in order of increasing or decreasing complexity, or can be specified by the user. The appropriate layout processing actions are applied to matching portions of the IC layout to form the corrected photomask layout. This process can be sequential or batch mode. Shape and action conflicts can be resolved by marking identified/modified elements or by designing rules for orderly resolution of any inconsistencies or overlaps.
224 citations
Patent•
07 Jun 2002TL;DR: In this paper, the phase information is incorporated into a cell-based design methodology and phase sets are selected based on the ability to phase shift the features within the cell C by creating a phase set for most of the cells of a cell library.
Abstract: Phase information is incorporated into a cell-based design methodology Standard cells have four edges: top, bottom, left, and right The top and bottom edges have fixed phase shifters placed, eg 0 A given cell C will have a phase set created with two versions: 0-180 (left-right) as well as 180-0 Alternatively, the same phase set: 0—0 and 180—180 could be created for a cell The phase sets are selected based on the ability to phase shift the features within the cell C By creating a phase set for most of the cells of a cell library, standard cell placement and routing techniques can be used and phase can then be quickly assigned using a simple ripple technique This ensures a phase compliant design upfront for the standard cell areas In some instances, phase sets are created for every cell in a library
209 citations