Topic
Photomask
About: Photomask is a research topic. Over the lifetime, 7917 publications have been published within this topic receiving 54524 citations. The topic is also known as: photoreticle & reticle.
Papers published on a yearly basis
Papers
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IBM1
TL;DR: In this article, a three-step methodology is presented to identify the causes of line width variation with distinct spatial signatures by spatial analysis, and sources with similar spatial signatures are then separated by contributor-specific measurements.
Abstract: Characterization of line width variation by a three-step methodology is presented. Causes of line width variation with distinct spatial signatures are first isolated by spatial analysis. Sources with similar spatial signatures are then separated by contributor-specific measurements. Unanticipated components are lastly identified by examination of the residual from spatial analysis. Significant sources include photomask error, flare, aberrations, development non-uniformity, and scan direction asymmetry. These components are synthesized to quantify the contributions from the three modules of the patterning process: photomask, exposure system, and post-exposure processing. Although these modules are independent of one another their effects on line width variation may be correlated. Moreover, the relative contributions of the modules are found to vary with exposure tool, development track, and lithography strategy, affirming the usefulness of the methodology in process tracking and optimization.
13 citations
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15 Dec 2003
TL;DR: The properties of a second-generation DUV laser pattern generator based on spatial light modulator technology and designed to meet the requirements of the 90-nm to 65-nm technology nodes are presented and major changes compared to its predecessor are pointed out.
Abstract: This paper presents the properties of a second-generation DUV laser pattern generator based on spatial light modulator technology and designed to meet the requirements of the 90-nm to 65-nm technology nodes. The system, named Sigma7300, is described and major changes compared to its predecessor are pointed out. These changes result in improved pattern accuracy and fidelity as well as system reliability and maintenance. This improved performance is accompanied with greatly reduced writing times of typically 3 Hrs. per mask. Performance data is presented that shows the system meets the resolution requirement of 260 nm with CD linearity of 10 nm and assist line resolution of 140 nm. CD uniformity data and registration data are also presented that indicates that the system meets the requirements for most layers at the 90-nm and 65-nm nodes.
13 citations
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06 Oct 2011TL;DR: In this article, the authors demonstrate the in-die capability of PROVE and present corresponding measurement results for short-term and long-term measurements as well as the attainable accuracy for feature sizes down to 85nm using different illumination modes and mask types.
Abstract: According to the ITRS roadmap, semiconductor industry drives the 193nm lithography to its limits, using techniques like
double exposure, double patterning, mask-source optimization and inverse lithography. For photomask metrology this
translates to full in-die measurement capability for registration and critical dimension together with challenging
specifications for repeatability and accuracy. Especially, overlay becomes more and more critical and must be ensured on
every die. For this, Carl Zeiss SMS has developed the next generation photomask registration and overlay metrology tool
PROVE® which serves the 32nm node and below and which is already well established in the market. PROVE® features
highly stable hardware components for the stage and environmental control. To ensure in-die measurement capability,
sophisticated image analysis methods based on 2D correlations have been developed.
In this paper we demonstrate the in-die capability of PROVE® and present corresponding measurement results for shortterm
and long-term measurements as well as the attainable accuracy for feature sizes down to 85nm using different
illumination modes and mask types. Standard measurement methods based on threshold criteria are compared with the
new 2D correlation methods to demonstrate the performance gain of the latter.
In addition, mask-to-mask overlay results of typical box-in-frame structures down to 200nm feature size are presented. It
is shown, that from overlay measurements a reproducibility budget can be derived that takes into account stage, image
analysis and global effects like mask loading and environmental control. The parts of the budget are quantified from
measurement results to identify critical error contributions and to focus on the corresponding improvement strategies.
13 citations
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21 May 2006TL;DR: A character size optimization technique to enhance the throughput of maskless lithography as well as photomask manufacture by minimizing the number of electron beam shots by optimizing the size of characters, which are the patterns to project and are placed on CP masks.
Abstract: We propose a character size optimization technique to enhance the throughput of maskless lithography as well as photomask manufacture. The number of electron beam shots to draw the patterns of circuits is a dominant factor in the manufacture time and the cost for devices. Our technique is capable of drastically reducing them by optimizing the size of characters, which are the patterns to project and are placed on CP masks. Experimental results show that our technique reduced 72.0% of EB shots in the best case, comparing with the ad hoc character sizing.
13 citations
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IBM1
TL;DR: In this paper, IBM developed a silane substituted alternating copolymer based 193nm bilayer resist system and demonstrates sub-120nm resolution using Nikon 0.6NA stepper with Chrome on Glass (COG) mask.
Abstract: 193nm lithography will be the future technology for sub- 150nm resolution. As the dimensions get smaller, resist thickness is also needed to be reduced for better resolution and wider process window. Single layer 193nm resist, with thickness of less than 500nm, may not be able to satisfy some of the substrate etch requirement. With bilayer resist scheme, the thin resist offers the advantages of high resolution and good process window. The thick underlayer provides the etch resistance required for substrate etching. IBM has developed a silane substituted alternating copolymer based 193nm bilayer resist system and demonstrates sub-120nm resolution using Nikon 0.6NA stepper with Chrome on Glass (COG) mask. Lithographic performance and formulation optimizations of this 193nm bilayer resist as well as underlayer evaluation and some etch study will be discussed.
13 citations