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.

Optical-softlithographic technology for patterning on curved surfaces

Abstract: We have established a novel concept of hybrid lithographic technology for non-planar surface patterning. Softlithography and photolithography are properly combined to transfer micro-patterns onto a curved area in an easy, low-cost way. As a first step, a film type of a photomask with micro-metal features is fabricated by the direct pattern transfer technique that has been presented in our preliminary work. Then, a flexible polymer photomask is wrapped on a curved surface to make conformal contact, and a variety of micro-features are formed on the surface via the photolithographic process. We have confirmed the validity of the technique for application in the industrial process by comparing the results transferred via the conventional photolithography with a rigid flat photomask. Subsequently, 3D polymer structures with a high aspect ratio (A/R) are fabricated on curved surfaces using this technique, followed by a discussion on several drawbacks due to the shape of the substrate. Overall, this paper has demonstrated a new method of micro-patterning, which would promise an emerging field of micro-fabrication on non-planar substrates.

Method and System for Forming Patterns with Charged Particle Beam Lithography

Abstract: A method for mask data preparation (MDP) is disclosed, in which a set of shots is determined that will form a pattern on a reticle, where the determination includes calculating the pattern that will be formed on a substrate using an optical lithographic process with a reticle formed using the set of shots. A method for optical proximity correction (OPC) or MDP is also disclosed, in which a preliminary set of charged particle beam shots is generated using a preliminary mask model, and then the shots are modified by calculating both a reticle pattern using a final mask model, and a resulting substrate pattern. A method for OPC is also disclosed, in which an ideal pattern for a photomask is calculated from a desired substrate pattern, where the model used in the calculation includes only optical lithography effects and/or substrate processing effects.

Method of exposure, photomask, method of production of photomask, microdevice, and method of production of microdevice

Abstract: A method of exposure projecting and exposing a pattern formed on a mask on to a photosensitive substrate through a projection optical system, comprising the steps of measuring a position of an image projected by said projection optical system; and projecting and exposing said pattern of the mask in a state with imaging characteristics corrected to reduce an amount of offset of a position of said projected image from an ideal position.

Gray scale all-glass photomasks

Abstract: A narrowly defined range of zinc silicate glass compositions is found to produce High Energy Beam Sensitive-glass (HEBS-glass) that possesses the essential properties of a true gray level mask which is necessary for the fabrication of general three dimensional microstructures with one optical exposure in a conventional photolithographic process. The essential properties are (1) A mask pattern or image is grainiless even when observed under optical microscope at 1000× or at higher magnifications. (2) The HEBS-glass is insensitive and/or inert to photons in the spectral ranges employed in photolithographic processes, and is also insensitive and/or inert to visible spectral range of light so that a HEBS-glass mask blank and a HEBS-glass mask are permanently stable under room lighting conditions. (3) The HEBS-glass is sufficiently sensitive to electron beam exposure, so that the cost of making a mask using an e-beam writer is affordable for at least certain applications. (4) The e-beam induced optical density is a unique function of, and is a very reproducible function of electron dosages for one or more combinations of the parameters of an e-beam writer. The parameters of e-beam writers include beam acceleration voltage, beam current, beam spot size, addressing grid size and number of retraces. A method of fabricating three-dimensional microstructures using HEBS-glass gray scale photomask for three dimensional profiling of photoresist and reproducing the photoresist replica in the substrate with the existing microfabrication methods normally used for the production of microelectronics is described.