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 etching polytmide film

Abstract: PROBLEM TO BE SOLVED: To obtain an etched product which retains flexibility fit for conveyance by a reel-to-reel system and has stabilized etching sizes and shapes of holes, etc., without impairing the flexibility a patterned resin layer mask when a photosensitive resin layer formed on the surface of a polyimide film is irradiated with UV through a photomask and developed to form the patterned resin layer mask and the polyimide film is etched with an alkaline solution. SOLUTION: A photosensitive resin layer formed on the surface of a polyimide film is irradiated with UV through a photomask and developed to form a patterned resin layer mask, irradiation with UV is carried out again in such a way that only the surface of the patterned resin layer mask is cured and the polyimide film is etched with an alkaline solution.

Foreign matter detection device

Abstract: A foreign matter detection device, for detecting a foreign matter on a photomask of transparent material with opaque patterns formed thereon, includes a laser source for emitting an S-polarized laser beam so as to impinge on a first surface of the photomask which reflects a P-polarized laser beam. A light source is provided to illuminate the photomask at an opposed surface to the first surface, from which a light transmits. This reflected P-polarized laser beam and transmitted light enters, through a condenser lens and a deflection plate, into a CCD in which an image representing the condition of the impinged surface is obtained. Since the P-polarized laser beam indicative of the corner edge of the pattern is offset by the transmitted light passing around the same corner edge, the pattern image is obscured and foreign matter is distinguishable in the obtained image.

Manufacturing use of photomasks with an opaque pattern comprising an organic layer photoabsorptive to exposure light with wavelengths exceeding 200 nm

Abstract: A method is provided for well printing a specified pattern even when the exposure treatment using a resist mask uses exposure light with a wavelength over 200 nm. When exposure treatment is applied to a semiconductor wafer by using exposure light with a wavelength over 200 nm, a photomask is used. The photomask is provided with an opaque pattern of a resist layer on an organic layer which is photoabsorptive in reaction to exposure light.

Mask induced polarization effects at high NA

Abstract: It is important to understand how a photomask will polarize incident radiation. This paper presents data collected on binary mask and various attenuated phase shifting mask materials, feature sizes, duty ratios, and illumination schemes via rigorous coupled wave analysis, extinction spectroscopy, and 193nm lithographic evaluation. Additionally, the result of polarization effects due to the photomask on imaging has been studied. It was found that in the majority of the cases, higher NA led to greater polarization effects. All mask materials predominantly pass the TM polarization state for the 0 order, whereas different materials and duty ratios affect the polarization of the first diffracted orders differently. The polarization effects contributed by mask materials being considered for use in high NA imaging systems need to be examined. The degree of polarization as a function of n and k is presented, providing an introduction to the desirable properties of future mask materials. Materials with higher refractive indices and lower extinction coefficients tend to pass more of the TM polarization state, which is undesirable. Materials with lower indices and relatively wide range of extinction coefficients pass more TE polarized radiation. The duty ratio, critical dimension, mask material, material thickness, and illumination scheme all influence mask induced polarization effects.© (2005) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Predictive model of the cost of extreme ultraviolet lithography masks

Abstract: A model has been developed to predict the cost of extreme ultraviolet lithography (EUVL) masks. The mask blank for EUVL consists of a low thermal expansion material substrate having a square photomask form factor and is coated with reflective Mo/Si multilayers. Absorber layers are deposited on the multilayer and patterned. EUVL mask patterning will use evolutionary improvements in mask patterning and repair equipment. One of the challenges in implementing EUVL is to economically fabricate multilayer-coated mask blanks with no printable defects. The model of mask cost assigns yield and time required for each of the steps in fabricating EUVL masks from purchase of a polished substrate to shipment of a patterned mask. Data from present multilayer coating processes and present mask patterning processes are used to estimate the future cost of EUVL masks. Several of the parameters that significantly influence predicted mask cost are discussed in detail. Future cost reduction of mask blanks is expected from learning on substrate fabrication, improvements in low defect multilayer coating to consistently obtain <0.005 defects cm -2 , and demonstration of multilayer smoothing which reduces the printability of substrate defects. The model predicts that the price range for EUVL masks in production will be $30-40K, which is comparable to the price of complex phase shift masks needed to use optical lithography for 70 nm critical dimension patterning.