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.

Mask aspects of EUVL imaging at 27nm node and below

Abstract: EUVL requires the use of reflective optics including a reflective mask. The mask consists of an absorber layer pattern on top of a reflecting multilayer, tuned for 13.53 nm. The EUVL mask is a complex optical element with many parameters contributing the final wafer image quality. Specifically, the oblique incidence of light, in combination with the small ratio of wavelength to mask topography, causes a number of effects which are unique to EUV, such as an HV CD offset. These so-called shadowing effects can be corrected by means of OPC, but also need to be considered in the mask stack design. In this paper we will present an overview of the mask contributors to imaging performance at the 27 nm node and below, such as CD uniformity, multilayer and absorber stack composition, thickness and reflectivity. We will consider basic OPC and resulting MEEF and contrast. These parameters will be reviewed in the context of real-life scanner parameters both for the NXE:3100 and NXE:3300 system configurations. The predictions will be compared to exposure results on NXE:3100 tools, with NA=0.25 for different masks. Using this comparison we will extrapolate the predictions to NXE:3300, with NA=0.33. Based on the lithographic investigation, expected requirements for EUV mask parameters will be proposed for 22 nm node EUV lithography, to provide guidance for mask manufacturers to support the introduction of EUV High Volume Manufacturing.

Manufacturing method of thin film transistor array substrate

Abstract: The invention relates to a manufacturing method of a thin film transistor array substrate. The manufacturing method comprises the following steps: a first photomask is utilized to form a continuous grid scanning line and an intermittent data line on a first metal layer simultaneously; a second photomask is utilized to carry out island carving and hole carving on a grid insulating layer, a semiconductor layer and an ohm contact layer; finally, a third photomask is utilized to form a source electrode, a drain electrode, a pixel electrode and a jumper electrode, wherein the pixel electrode is connected with the drain electrode, the jumper electrode is connected with the source electrode, and the jumper electrode connects two adjacent data lines by contact holes. The invention has the advantages of omitting the procedure of manufacturing a second metal layer and a passivation layer, reducing the number of the photomasks to three, shortening the process time and lowering cost.

Holographically produced image arrays for photolithography

Abstract: This disclosure describes the generation of multiple identical images holographically. Wavefronts from a unit pattern and a pinhole array separately illuminated by branched, spatially filtered and collimated laser beams are Fourier-transformed and focused in front of a holographic medium. Illumination of the developed hologram with a laser beam conjugate to the wavefront from one of the pinholes produces a spaced array of real images of the unit pattern. The process is useful in photomask making, or as a way to directly expose photoresist in silicon device manufacture.

Cost of ownership analysis for patterning using step and flash imprint lithography

Abstract: While the critical dimension in the microelectronics industry is continually going down due to developments in photolithography, it is coming at the expense of exponential increase in lithography tool costs and rising photomask costs. Step and Flash Imprint Lithography (S-FIL) is a nano-patterning technique that results in significantly lower cost of the lithography tool and process consumables. In this study, a comparison of S-FIL with Extreme Ultraviolet (EUV) photolithography technique is provided at the 50nm node. Advantages and disadvantages of S-FIL for various application sectors are provided. Finally, cost of ownership (CoO) computations of S-FIL versus EUV is provided. CoO computations indicate that S-FIL may be the cost-effective technology in the sub-100nm domain, particularly for emerging devices that are required in low volumes.

Gray scale fabrication method using a spin-on glass material and integrated optical designs produced therefrom

Abstract: The subject invention relates to the fabrication of micro-optical structures in a glass-like transparent material using conventional photolithography processing steps. The glass-like material is a spin-on glass (SOG) material, which behaves like a negative-tone photoresist, and has high quality optical properties similar to those of glass. The present invention can take advantage of gray scale photomasks to illuminate the uncured spin-on material with various illumination intensities, thus resulting in variations in resultant film thickness of the SOG material after the chemical development step. This results in micro-optical structures that can be fabricated with the desired shapes, depending on the transmission characteristics of each region of the gray scale photomask.