T
Tadao Yasuzato
Researcher at NEC
Publications - 23
Citations - 452
Tadao Yasuzato is an academic researcher from NEC. The author has contributed to research in topics: Phase-shift mask & Resist. The author has an hindex of 10, co-authored 23 publications receiving 450 citations.
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Patent
Process of forming bump on electrode of semiconductor chip and apparatus used therefor
Tadao Yasuzato,Keizo Sakurai +1 more
TL;DR: In this article, a process of forming bumps on respective electrodes (118a to 118v) of a semiconductor chip (SC21) comprises the steps of a) preparing a bonding apparatus equipped with a bonding tool (114) three-dimensionalally movable, b) forming a small ball at the leading end of a bonding wire passing through the bonding tool, c) causing the tool to press the small ball against the upper surface of one of the electrodes for bonding thereto, d) moving the tool in a direction leaving from the upper surfaces of the electrode by a distance
Patent
Optical proximity correction halftone type phase shift photomask
Shinji Ishida,Tadao Yasuzato +1 more
TL;DR: In this paper, a part of a mask pattern is changed from opaque to halftone, thus improving the resist pattern fidelity, and a light screen layer is formed on the halftones layer.
Patent
Photomask and exposure method using a photomask
Tadao Yasuzato,Shinji Ishida +1 more
TL;DR: In this article, a photomask in which contrast of light intensity of a pattern to be transferred (main pattern) is enhanced on an image plane while transfer of auxiliary pattern themselves is suppressed is described.
Patent
Photo mask and fabrication process therefor
Tadao Yasuzato,Shinji Ishida +1 more
TL;DR: In this paper, a light shielding layer 2 of ruthenium in a thickness of 70 nm and a reflection preventing layer 3 of a Ruthenium oxide in thickness of 30 nm, and a photosensitive resin layer, a sililated layer is formed by electron beam lithography and sililation.
Proceedings ArticleDOI
Large assist feature phase-shift mask for sub-quarter-micrometer window pattern formation
TL;DR: In this article, a large assist feather technique has been proposed to improve the depth of focus of isolated windows, which uses the assist features having almost the same size as main patterns, and the quartz substrate was vertically etched at the assist feature.