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.

Repair of reflective photomask used in semiconductor process

Abstract: A reflective photomask is fabricated enabling photolithographic processes at wavelengths as low as 100 nm, with preferred embodiments enabling processes at wavelengths of 150-200 nm. Reflective photomask defects of the type where material is missing are repaired by locally depositing material over the defective area. The deposit area is then trimmed, if needed, to remove excess material. The deposited material has substantially the same reflectivity and phase as the adjacent mask area. Chemical-mechanical polishing (CMP) or another planarizing process is used to smooth the defect area with the deposited material. The planarizing process prevents height differentials or border variations on the mask surface between the region where the material is deposited and the surrounding regions.

Apparatus for detecting the defects of the mask pattern using spatial filtering

Abstract: Two kinds of light sources, one of which emits a coherent light and the other of which emits incoherent light, are provided. The coherent light and incoherent light respectively emitted from the two different kinds of light sources, proceed on the same optical axis. A photomask, such as for an integrated-circuit, or other objects, which have linear straight line features and nonlinear defects, are simultaneously illuminated by the coherent light and incoherent light. The two kinds of light which pass through the photomask or other objects are transformed into a Fourier-transform pattern by a transform lens. A spatial filter, having a plurality of arms which extend in predetermined directions from the center thereof, is provided on the focal plane of the transform lens. The spatial filter suppresses the passing of coherent light having information of the linear straight line features. The coherent light which has information of the defects of the photomask is not suppressed by the spatial filter. The coherent light and incoherent light passing through the spatial filter are directed to an image plane. As a result thereof, an image of the photomask or other object, obtained by the incoherent light and an image of the defects of the photomask or other objects obtained by the coherent light, are simultaneously projected on each other on the image plane.

Digital scan model for focused ion beam induced gas etching

Abstract: Focused ion beam (FIB), assisted, gas etching has several advantages over physical sputtering in many FIB applications. Advantages include etch rate enhancements of 1–2 orders of magnitude, dramatically reduced redeposition of etched material on sidewalls in high‐aspect ratio structures, and reduced implantation of the primary ion species in the sample. Applications which benefit from FIB gas etching include photomask and x‐ray mask defect repair, integrated circuit modification for failure analysis, and sample preparation for scanning electron microscope and transmission electron microscope analysis. In this article, a simple model is presented which takes into account the ion beam and scanning parameters, gas flux, and basic material constants. Approximate formulas are given in terms of these parameters and compared to experimental results.

Fabricating multilevel SU-8 structures in a single photolithographic step using colored masking patterns

Abstract: The fabrication of multilevel SU-8 structures using a single photolithographic masking step is described. Preliminary data are presented on the use of photolithographic masks, containing millimeter-scale colored patterns, printed on transparent films using a standard color laser printer. The different colors printed on the photomask are shown to have differences in their UV absorptions, and hence different structure levels can be achieved from a single exposure. This method eliminates the pixelation problems encountered when using gray-scale masks (without employing photoreduction techniques) generated using a black-and-white laser printer. For research applications requiring rapid prototyping and fast turnaround times for large-scale features, this technique offers a cost-effective and time-efficient alternative to current three-dimensional lithography methods, which typically make use of multiple binary masks, alignment procedures, and exposures. Future applications will include the fabrication of textured PDMS surfaces and PDMS microfluidic substrates, cast from SU-8 molds processed using this technique.

Photomask and method of crystallizing semiconductor thin film

Abstract: PROBLEM TO BE SOLVED: To provide a photomask which permits the formation of a high-quality polycrystalline material with a large crystal grain diameter. SOLUTION: The photomask comprises a plurality of first mask sections 2a, 2b, and 2c wherein a plurality of rectangular first slits 1 are each formed, and a second mask section 4 wherein a plurality of rectangular second slits 3 are formed. After conducting a treatment for making a grain diameter of polysilicon larger using the first mask section 2 wherein the first slits 1 are formed, projections 20 formed by this treatment are made lower using the second mask section 4 wherein the second slits 3 are formed. Consequently, a surface of a semiconductor thin film 21 can be flattened, resulting in the formation of a polysilicon TFT having superior electric properties. COPYRIGHT: (C)2004,JPO