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.

Method for photomask plasma etching using a protected mask

Abstract: A method for etching chromium and forming a photomask is provided. In one embodiment, a method for etching chromium includes providing a film stack in a processing chamber having a chromium layer, patterning a photoresist layer on the film stack, depositing a conformal protective layer on the patterned photoresist layer, etching the conformal protective layer to expose a chromium layer through the patterned photoresist layer, and etching the chromium layer. The methods for etching chromium of the present invention are particularly suitable for fabricating photomasks.

Focused-ion-beam repair of phase-shift photomasks

Abstract: Phase-shift photolithography is emerging as an important new technology for sub-half-micron design rule circuits. Unfortunately part of the price paid for the improvements in spatial resolution and process latitude afforded by phase-shift lithography is increased mask defect printing sensitivity. The minimum printable defect size, 0.3 microns (on the mask) for I-line steppers at 0.35 microns, is roughly half that for conventional photomasks. This paper examines the issues associated with extending high resolution focused ion beam mask repair to phase-shift masks.

Preparation of photomask blank and photomask

Abstract: A photomask blank is prepared by forming a light-absorbing film on a transparent substrate, and irradiating the light-absorbing film with light from a flash lamp at an energy density of 3 to 40 J/cm 2 . A photomask is prepared by forming a resist pattern on the photomask blank by photolithography, etching away those portions of the light-absorbing film which are not covered with the resist pattern, and removing the resist.

Design, simulation, and fabrication of three-dimensional microsystem components using grayscale photolithography

Abstract: Grayscale lithography is a widely known but underutilized microfabrication technique for creating three-dimensional (3-D) microstructures in photoresist. One of the hurdles for its widespread use is that developing the grayscale photolithography masks can be time-consuming and costly since it often requires an iterative process, especially for complex geometries. We discuss the use of PROLITH, a lithography simulation tool, to predict 3-D photoresist profiles from grayscale mask designs. Several examples of optical microsystems and microelectromechanical systems where PROLITH was used to validate the mask design prior to implementation in the microfabrication process are presented. In all examples, PROLITH was able to accurately and quantitatively predict resist profiles, which reduced both design time and the number of trial photomasks, effectively reducing the cost of component fabrication.

Progress in the fabrication of low-defect density mask blanks for extreme ultraviolet lithography

Abstract: Extreme ultraviolet lithography (EUVL) is the leading next-generation lithography (NGL) technology to succeed optical lithography at the 32-nm node and beyond. The technology uses a multilayer-based reflective optical system, and the development of suitable, defect-free mask blanks is the greatest challenge facing the commercialization of EUVL. We describe recent progress toward the development of a commercial tool and process for the production of EUVL mask blanks. Using the resources at Mask Blank Development Center at SEMATECH-North in Albany, New York, we are able to decrease the mean multilayer-coating-added defect density on 6-in. square quartz substrates by almost an order of magnitude, from ~0.5 defects/cm2 to ~0.055 defects/cm2 for particles 80 nm in size (polystyrene latex equivalent). We also obtain a "champion" mask blank with an added defect density of only ~0.005 defects/cm2. This advance is due primarily to a compositional analysis of the particles using focused ion beam and energy dispersive analysis of x-rays (EDX) followed by tool and procedural upgrades based on best engineering practices and judgment. Another important specification for masks blanks is the coating uniformity, and we have simultaneously achieved a centroid wavelength uniformity of 0.4% and a coating-added defect density of 0.06 def/cm2.