Abstract: A method of inspecting defect of a mask is provided. In this method, a database for storing a plurality of virtual simulation models is created. The virtual simulation models are determined by a plurality of factors including an optical effect and a chemical effect during the transferring the pattern of a mask to the photoresist layer on a wafer. A mask defect image is acquired. A simulation contour of the mask defect image is generated from at least one virtual simulation model in the database. Next, the acceptability of the mask is determined.

Abstract: A method of verifying a layout pattern comprises separately steps of obtaining a simulated pattern at a lower portion of a film by using a layout pattern as a mask to transfer the layout pattern to the film, and obtaining a simulated pattern at an upper portion of the film by using the layout pattern as a mask to transfer the layout pattern to the film. The layout pattern is verified according to the upper and lower simulated patterns.

Abstract: A method for correcting a photomask pattern is provided. The correcting method performs a verification of a focus-exposure matrix (FEM) and an overlay variation on a layout area having contact holes or vias in a layout pattern so as to generate a hint information. The layout pattern of the photomask is corrected according to the hint information to prevent the contact holes or vias from being exposed in arrangement to corresponding metal layer, poly layer, or diffusion layer.

Abstract: A reticle includes a reticle body having a first surface, a pattern disposed on the first surface of the reticle body, and at least a protection layer disposed on the first surface of the reticle body. The protection layer is in contact with the first surface of the reticle body.

Abstract: A customer illumination aperture (CIA) structure for lithographic exposure is disclosed, including a central part and at least one off-axis part around the central part. The off-axis part of the CIA is disposed in a symmetric manner with respect to the central part.

Abstract: The method of forming the photo resist feature comprises forming a photo resist layer on the substrate, providing a photo mask comprises the main feature and the assistant feature, providing the exposure process to form the photo resist main feature and the photo resist assistant feature correspondingly and providing the trimming process to remove the photo resist assistant feature and trim the photo resist main feature. The method reduces OPE and larges the process window.

Abstract: A method for improving illumination uniformity in an exposure process is described, wherein a light source, a reticle and a projection system are used to expose a substrate in the exposure process. A realtime adjustable gray filter like a gray LCD panel is placed in the light path between the light source and the exposed substrate to compensate the illumination nonuniformity on the substrate in real time.

Abstract: A method for reducing critical dimension is provided. An exposure process and a develop process are performed on a photoresist layer. An optical trim exposure process is performed between the exposure process and the development process or before the exposure process. The optical trim expsoure process is performed to expose the photoresit layer by using a fully open mask of which the transmission rate is greater than zero. Because of the performance of the optical trim exposure process, the critical dimension of the photoresist layer can be reduced without substantially changing the characteristics of the photoresist layer.

Abstract: An overlay mark for concurrently monitoring alignment accuracy, focus, leveling and astigmatism and a method of application thereof are disclosed. The overlay mark comprises four inner bars and four outer bars formed at the corners of exposure areas. The inner bar has a sawtooth area and a bar-shaped area, and the outer bar is a fore-layer etched pattern. Both the inner bars and the outer bars are formed into rectangles, and each bar is one side of a rectangle and none of the sides are connected. The sawtooth areas of the inner bars disposed on opposite sides are located at a same position. The rectangle formed by the outer bars encloses the rectangle formed by the inner bars. During the monitoring process, a testing beam scans across a scan area being divided into two areas, i.e., one being the outer bars and the sawtooth area of the inner bars, and the other one being the outer bars and the bar-shaped area of the inner bars.