Mask inspection

About: Mask inspection is a research topic. Over the lifetime, 1072 publications have been published within this topic receiving 8696 citations.

Mask inspecting method and inspecting device

Abstract: PROBLEM TO BE SOLVED: To perform a rapid mask inspection for a stencil mask and the like used for the manufacturing process of a microelectronic circuit. SOLUTION: Incident light emitted from a light source is converted via a spectroscope for incident light into monochromatic light, and is incident on a mask (a stencil mask) 5 to be inspected on a mask stage 6. The mask stage 6 is controlled by a computer 8 for controlling. The light transmitted through the stencil mask 5 is detected by a light detector 12 after elimination of undesired light by a spectroscope 11 for detection. The detected signal is stored by the computer 8 for controlling. The mask 5 to be inspected can be inspected from the spectrum or cutoff wavelength of the detected light.

Fabrication and pattern transfer of optical proximity correction (OPC) mask

Abstract: An application of a mask with serif patterns to a 0.8 micrometers rule mask ROM programming layer is discussed. A serif pattern is the unprinting size pattern added to the corner of original pattern. It suppresses the corner rounding caused by the lack of resolution performance of a lithography exposure system. We aimed to make 1.0 micrometers square pattern with g-line (436 nm). There are some difficulties in application of optical proximity correction (OPC) mask. One of the problems is the optimization of the mask design to be applied to get the appropriate correction effect. We evaluated it by simulation and experiment. The second is the increase in EB data volume. We split mask data into periodic common data with serifs for cell pattern and random ROM code data for programming to compact the data volume. The other is the printability and inspection of mask defects. The OPC mask shows the high printability of defects because of the violation of the mask design. To detect all the printable defects, mask inspection needs high sensitivity. In the inspection with high sensitivity, the extrusion of pattern caused by EB proximity effect becomes to be detected as false defect. To reduce the false defects, we optimized the EB exposure process. In order to use the OPC masks in actual production, mask design for application should be optimized not only in the viewpoint of pattern correction effect but also in the viewpoint of mask fabrication and inspection.

Inspection device for photomask, inspection method for photomask, method for manufacturing photomask for manufacturing liquid crystal device, and pattern transfer method

Abstract: PROBLEM TO BE SOLVED: To provide an inspection device for a photomask capable of carrying out preferable performance evaluation and defect inspection of a large photomask while suppressing the increase in an installing area of the device, and capable of ensuring safeness and handling property for a large photomask. SOLUTION: A photomask 3 is held and irradiated with a light flux at a predetermined wavelength emitted from a light source 1 through an illumination optical system 2, and the image of the photomask 3 is imaged by an imaging means 5 through an objective lens system 4. The image of the photomask 3 is imaged by aligning the optical axes of the illumination optical system 2, the objective lens system 4 and the imaging means 5 and by operating the objective lens system 4 and the imaging means 5 to mutually and independently move in the optical axis direction. COPYRIGHT: (C)2008,JPO&INPIT

Map creation method, mask inspection method, and mask inspection device

Abstract: PROBLEM TO BE SOLVED: To provide a map creation method, a mask inspection method, and a mask inspection device, which are capable of inspecting defects of masks having fine patterns at a low cost with high accuracy.SOLUTION: A stage is moved in Z-direction oppositely from a curvature direction by a moving amount corresponding to a curvature degree of a reference mask; a reference surface map is created based on contrast values of an optical image formed by light irradiated on a reference mask through a transmissive member and an optical system; the stage is moved in the Z-direction oppositely from a curvature direction by a moving amount corresponding to a curvature degree of the reference surface; a curvature degree of an inspection-target mask is acquired based on contrast values of an optical image formed by light irradiated to the inspection-target mask through the transmissive member and the optical system; and a sum or difference of the curvature degree of the reference surface and the curvature degree of the inspection-target mask is acquired as a deviation amount in the Z-direction between the inspection-target mask and a focus position of the optical system to create a defocus map.SELECTED DRAWING: Figure 3

Development of highly spatial-coherent, 13.5-nm high-order harmonics for EUVL mask inspection using coherent EUV scatterometry microscope

Abstract: We demonstrate the generation of low divergence, spatially coherent, high-order harmonics (orders ranging from 23rd to 95th) using commercial sub-TW laser system. The 6 mJ, 32 fs laser pulses were loosely focused with f/125 concave mirror in a semi-infinite gas cell. The beam divergence was measured to be 0.18-mrad at the 59th harmonics (13.5 nm) in 18kPa of helium. The 59th harmonics with novel high-throughput, spatial beam separator, which has attenuation ratio of 0.01 for the pump pulse, was used to detect line-defects in extreme-ultraviolet lithography mask. A 2nm-wide line-defect in an 88-nm line-and-space pattern was successfully detected using diffraction imaging technique.