Takanori Sutou has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
Abstract: A photomask which improves the imaging performance that the photomask has and forming a good micro image on a wafer in photolithography with a half pitch of 60 nm or less. Provided is a photomask used for photolithography using an ArF excimer laser as an exposing source for immersion exposure by quadrupole-polarized illumination with a high-NA lens. The photomask includes a mask pattern of a light shielding film or semi-transparent film on a transparent substrate, and further, given that a thickness of the light shielding film or semi-transparent film is “t” nm, a refractive index is “n”, an extinction factor is “k”, and a bias of a space part of the mask pattern is “d” nm, when “t”, “d”, “n” and “k” are adjusted and the photomask is used for the photolithography, optical image contrast takes a value exceeding 0.580.
Abstract: A photomask which improves the imaging performance that the photomask has and forming a good micro image on a wafer in photolithography with a half pitch of 60 nm or less. Provided is a photomask used for photolithography using an ArF excimer laser as an exposing source for immersion exposure by quadrupole-polarized illumination with a high-NA lens. The photomask includes a mask pattern of a light shielding film or semi-transparent film on a transparent substrate, and further, given that a thickness of the light shielding film or semi-transparent film is “t” nm, a refractive index is “n”, an extinction factor is “k”, and a bias of a space part of the mask pattern is “d” nm, when “t”, “d”, “n” and “k” are adjusted and the photomask is used for the photolithography, optical image contrast takes a value exceeding 0.580.