Mask inspection

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

EUV mask: detection studies with Aera2

Abstract: The progress of optical lithography towards EUV wavelength has placed mask defectivity among major EUV program risks. Traditional mask inspection was carried in the DUV domain at 19x nm wavelength, similar to ArF lithography. As EUV mask patterns approach the 20nm half-pitch level, the resolution of DUV systems approaches its practical limits. At this limit, the lesson learned from ArF lithography is that contrast may be improved significantly by utilizing resolution enhancement techniques such as off-axis illumination shapes. Here we present an experimental study of the effects of illumination and polarization on contrast and detection. We measured a EUV patterned mask with programmed defects using Aera2 mask inspection tool at 193nm wavelength, equipped with a high NA objective. We compared the contrasts of the patterns and the defect detection signals obtained by employing 4 different illumination shapes and three polarization states: linear along x, linear along y, circular polarization. We learned that in order to achieve the best results both in terms of contrast and in terms of detection, it is most important to choose a suitable exposure conditions. In addition, a proper choice of the polarization state of the illumination can also result in some improvement.

Euv mask inspection.

Abstract: A system for inspecting an extreme ultra violet (EUV) mask. The system includes an array of sensors and an optical system. The array of sensors is configured to produce analog data corresponding to received optical energy. The optical system is configured to direct EUV light from an inspection area of an EUV patterning device onto the array of sensors, whereby the analog data is used to determine defects or to compensate for irregularities found on the EUV mask.

Current status of EUV mask inspection using 193nm optical inspection system in 30nm node and beyond

Abstract: Extreme Ultra Violet Lithography (EUVL) is one of the most advanced patterning technologies to overcome the critical resolution limits of current ArF lithography for 30nm generation node and beyond. Since EUVL mask manufacturing process has not been fully stabilized yet, it is still suffering from many defect issues such as blank defects, defects inside multilayer causing phase defects, CD defects, LERs (Line Edge Roughness), and so on. One of the most important roles in mask manufacturing process belongs to mask inspection tools, which monitor and visualize mask features, defects and process quality for the EUVL process development. Moreover, as the portion of EUV mask production has been increased due to the EUV Pre-Production Tool (PPT) development, mask inspection technologies for EUVL become highly urgent and critical to guarantee mask quality. This paper presents a promising inspection technique for increasing the contrast of pattern imaging and defects capture rate using configurable illumination conditions in 193nm wavelength inspection tool.

Method of manufacturing semiconductor integrated circuit device optical mask therefor, its manufacturing method, and mask blanks

Abstract: In order to suppress or prevent the occurrence of foreign matter in the manufacture of a semiconductor integrated circuit device by the use of a photo mask constituted in such a manner that a resist film is made to function as a light screening film, inspection or exposure treatment is carried out, when the photo mask 1 PA 1 has been mounted on a predetermined apparatus such as, e.g., an inspection equipment or aligner, in the state in which a mounting portion 2 of the predetermined apparatus is contacted with that region of a major surface of a mask substrate 1 a of the photo mask 1 PA 1 in which a light shielding pattern 1 b and a mask pattern 1 mr , each formed of a resist film, on the major surface of the mask substrate 1 a do not exist.

Aerial-image-based inspection of binary (OPC) and embedded-attenuated PSM

Abstract: The paper presents a revolutionary technology to inspect advanced contact layers. Instead of finding defects based on a size-dependent defect specification, defects are found according to their impact at the wafer CD result. The inspection methodology used is aerial imaging. The main advantage of this method is that only defects, which actually affect the wafer result, will be detected and classified. The paper presents first inspection results on contact layers designed for the 130nm and 90 nm technology node.