A camera acquires a 4D light field of a scene. The camera includes a lens and sensor. A mask is arranged in a straight optical path between the lens and the sensor. The mask including an attenuation pattern to spatially modulate the 4D light field acquired of the scene by the sensor. The pattern has a low spatial frequency when the mask is arranged near the lens, and a high spatial frequency when the mask is arranged near the sensor.

4D Light Field Cameras

Nanostructured photonic materials and associated components for use in devices and systems operating at ultraviolet (UV), extreme ultraviolet (EUV), and/or soft Xray wavelengths are described. Such a material may be fabricated with nanoscale features tailored for a selected wavelength range, such as at particular UV, EUV, or soft Xray wavelengths or wavelength ranges. Such a material may be used to make components such as mirrors, lenses or other optics, panels, lightsources, masks, photoresists, or other components for use in applications such as lithography, wafer patterning, biomedical applications, or other applications.

Materials, components, and methods for use with extreme ultraviolet radiation in lithography and other applications

The invention relates to a method for correcting at least one error on wafers processed by at least one photolithographic mask, the method comprises: (a) measuring the at least one error on a wafer at a wafer processing site, and (b) modifying the at least one photolithographic mask by introducing at least one arrangement of local persistent modifications in the at least one photolithographic mask.

Method and apparatus for correcting errors on a wafer processed by a photolithographic mask

Scanned probe oxidation (SPO) nanolithography has been performed with an atomic force microscope (AFM) on an octadecyl-terminated silicon (111) surface to create protuberant oxide line patterns under ambient conditions in contact mode. The kinetic investigations of this SPO process indicate that the oxide line height increases linearly with applied voltage and decreases logarithmically with writing speed. The oxide line width also tends to vary with the same law. The ambient humidity and the AFM tip state can remarkably influence this process, too. As compared with traditional octadecylsilated SiO2/Si substrate, such a substrate can guarantee the SPO with an obviously lowered voltage and a greatly increased writing speed. This study demonstrates that such alkylated silicon is a promising silicon-based substrate material for SPO nanolithography.

http://iopscience.iop.org/article/10.1088/0957-4484/17/1/057/pdf

Scanned probe oxidation on an octadecyl-terminated silicon (111) surface with an atomic force microscope: kinetic investigations in line patterning

Nanografting, an atomic force microscopy (AFM) based nanolithography technique, is becoming a popular method for patterning self-assembled monolayers (SAMs). In this technique, a nanoscale patch of a thiol-on-gold SAM is exchanged with a different thiol by the action of an AFM tip operated in contact mode at high load. The results are then imaged in topographic or lateral force microscopy again at low values of the load. One of the problems of contact mode nanografting is that monolayers of large molecules such as proteins are likely to be deformed, damaged, or even removed from the surface by contact mode imaging even when small loads are used. Furthermore, we need to note that the stiffness of the cantilevers used in contact mode is different than that of the cantilevers used in tapping mode and that tip changing in the course of an experiment can be quite inconvenient. Here, we show that a monolayer on a gold substrate can be nanografted using tapping mode AFM (also referred to as amplitude modulation AFM) rather than the commonly used contact mode. While the grafting parameters are somewhat trickier to choose, the results demonstrate that nanografting in tapping mode can make patches of the same quality as those made by contact mode, therefore allowing for gentle imaging of the grafted molecules and the whole SAM without changing the microscope tip.

Nanografting of alkanethiols by tapping mode atomic force microscopy.

Adjusting a curvature of a substrate includes forming at least one deformed portion in a predetermined region of a substrate, wherein the substrate includes a curved region before forming the at least one deformed portion, and forming the at least one deformed portion includes irradiating the substrate in the predetermined region so as to fixedly displace substrate material in the predetermined region.

Substrate including deformed portions and method of adjusting a curvature of a substrate

Provided are photomask registration errors of which have been corrected and a method of correcting the registration errors of a photomask. The photomask includes a photomask substrate, an optical pattern formed on one surface of the photomask substrate, and a plurality of stress generation portions formed in the photomask substrate. A method of correcting the registration errors of a photomask includes the steps of forming an optical pattern on a photomask substrate, measuring the registration errors of the optical pattern, and forming a plurality of stress generation portions in the photomask substrate so that the stress generation portions correspond to the measured registration errors.

Photomask registration errors of which have been corrected and method of correcting registration errors of photomask

Nano-oxidation of Si using ac modulation in atomic force microscope lithography

An applied bias voltage between the atomic force microscope tip and the substrate is one of the important factors related to the growth of oxide patterns A pulse modulator was used to apply a pulsed bias voltage that synchronizes with the resonance frequency of the cantilever between the tip and the substrate in tapping mode The height of the protruded oxide structure was increased for short duration times of the pulsed bias due to the reduction of built-up space charge in oxide The aspect ratio of patterns using pulsed bias voltage was about two times higher than that using continuous bias voltage This study revealed that the pulsed bias has an advantage for obtaining a higher aspect ratio pattern than the continuous bias by reducing the effect of space charge in oxide

http://iopscience.iop.org/article/10.1088/0957-4484/16/10/017/pdf

Atomic force microscope anodization lithography using pulsed bias voltage synchronized with resonance frequency of cantilever

The present invention relates to a method for manufacturing a reflective multi-layered thin film mirror for an extreme ultraviolet radiation (EUV) exposure process that is one of the next generation exposure process masks using an atomic force microscope (AFM). This reflective multi-layered thin film mirror for extreme ultraviolet radiation (EUV) exposure process allows metal oxide structures with fixed height and ' width to be obtained using anodic oxidization phenomenon between the cantilever tip of a atomic force microscope and an absorber material during the patterning of an absorber layer on a multi-layered thin film of a substrate, followed by forming the ultra-fine line width absorber patterns via etching of the metal oxide structure. Use of the manufacturing process of this invention is advantageous in manufacturing of extreme ultraviolet radiation exposure mask mirrors with high resolution and in manufacturing of reflective multi-layered thin film mirrors with minute absorber pattern sizes (less than 20 nm line width) compared to traditional manufacturing methods.

Sukjong Bae

Papers

Substrate including deformed portions and method of adjusting a curvature of a substrate

Photomask registration errors of which have been corrected and method of correcting registration errors of photomask

Nano-oxidation of Si using ac modulation in atomic force microscope lithography

Atomic force microscope anodization lithography using pulsed bias voltage synchronized with resonance frequency of cantilever

Fabrication method of extreme ultraviolet radiation mask mirror using atomic force microscope lithography