The invention provides a process for adjusting the friction coefficient and adhesion between a surface of a first solid object and a surface of a second solid object, which surfaces are movable with respect to each other when the solid objects are in contact with each other, wherein the surface roughness of at least one of the surfaces is adjusted by subjecting one or more selected parts of said first and/or second solidobjects to an electric fieldand/or a magnetic field, wherein at least said one or more selected partsof said first and/or second solid objectscomprise a piezo-electric material, and wherein other parts of said first and/or second solid object do not comprise a piezo-electric material. The invention further provides an object having a surface of which the roughness can be adjusted by subjecting one or more selected parts of the object to an electric fieldand/or a magnetic field, which selected parts comprise a piezo-electric material. In addition, the invention provides a system comprising said object.

Process for adjusting the coefficient of friction and/or adhesion between surfaces of two solid objects

An immersion projection optical system having, for example, a catadioptric and off-axis structure, reduces the portion of an image space filled with liquid (immersion liquid). The projection optical system, which projects a reduced image of a first plane onto a second plane through the liquid, includes a refractive optical element (Lp) arranged nearest to the second plane. The refractive optical element includes a light emitting surface (Lpb) shaped to be substantially symmetric with respect to two axial directions (XY-axes) perpendicular to each other on the second plane. The light emitting surface has a central axis (Lpba) that substantially coincides with a central axis (40a) of a circle (40) corresponding to a circumference of a light entering surface (Lpa) of the refractive optical element. The central axis of the light emitting surface is decentered in one of the two axial directions (Y-axis) from an optical axis (AX).

Projection optical system, exposure apparatus and exposure method

A system and process of an extreme ultraviolet lithography (EUVL) is disclosed. The system and process includes receiving a mask with two states, which have 180 degree phase difference to each other. These different states are assigned to adjacent main polygons and adjacent assist polygons of the mask. A nearly on-axis illumination (ONI) with partial coherence σ less than 0.3 is utilized to expose the mask to produce diffracted lights and non-diffracted lights. A majority portion of the non-diffracted lights and diffracted light with diffraction order higher than 1 are removed. Diffracted light having +1-st and −1-st diffracted order are collected and directed by a projection optics box (POB) to expose a target.

Extreme ultraviolet lithography process and mask

A reflective mask is described. The mask includes a low thermal expansion material (LTEM) substrate, a conductive layer deposited on a first surface of the LTEM substrate, a stack of reflective multilayers (ML) deposited on a second surface of the LTEM substrate, a capping layer deposited on the stack of reflective ML, a first absorption layer deposited on the first capping layer, a main pattern, and a border ditch. The border ditch reaches to the capping layer, a second absorption layer deposited inside the border ditch, and where the second absorption layer contacts the capping layer. In some instances, the border ditch crosses the capping layer and partially enters the reflective multilayer.

Reflective mask and method of making same

The present invention provides a system and method of modifying the mask layout shapes of an integrated circuit layout design to compensate for reticle field location-specific systematic CD variations resulting from mask writing process variations, lens imperfections in lithographic patterning, and photoresist process variations Called PLC (Process-optimized Layout Compensation), each set of compensation rules according to the present invention is specifically tailored for a particular mask-writer-patterning-tools-and-resist-process combination, and are performed on a reticle-wide basis Furthermore, for each geometric shape in the mask layout, the amount of modification is determined based on a categorization of the type of the shape, the specific location in the reticle field the particular shape falls in, its context (ie, surrounding patterns, orientation, etc), as well as certain photoresist parameters to be used in the patterning process

System and method for reducing patterning variability in integrated circuit manufacturing through mask layout corrections

The small-field exposure tool (SFET) for extreme ultraviolet (EUV) lithography was manufactured by Canon and EUVA and installed in Selete. It is being used for developing mask, resist, and tool technologies. In this paper, we review the current status of SFET development and present some initial results on lithographic performance and tool stability.

Extreme Ultraviolet Lithography Using Small-Field Exposure Tool: Current Status

Techniques for measurement of higher-order aberrations of a projection optical system in photolithographic exposure tools have been established. Even-type and odd-type aberrations are independently obtained from printed grating patterns on a wafer by three-beam interference under highly coherent illumination. Even-type aberrations, i.e., spherical aberration and astigmatism, are derived from the best focus positions of vertical, horizontal, and oblique grating patterns by an optical microscope. Odd-type aberrations, i.e., coma and three-foil, are obtained by detection of relative shifts of a fine grating pattern to a large pattern by an overlay inspection tool. Quantitative diagnosis of lens aberrations with a krypton fluoride (KrF) excimer laser scanner is demonstrated.

Aberration measurement from specific photolithographic images: a different approach

The effects of aberration and flare on the lithographic performance of the EUV small-field exposure tool (SFET)
were evaluated. Simulation results indicated that the effect of aberration on the image contrast of line-and-space (L&S)
patterns should be small. In exposure experiments, 26-45-nm L&S patterns were successfully fabricated under annular
illumination (σ=0.3/0.7). A key factor limiting resolution should be resist performance. Simulation results also indicated
that the astigmatic aberration could produce a focal shift of about 60 nm between horizontal and vertical L&S patterns.
The experimentally obtained focus shift agreed well with the simulation results. Dense 32-45-nm contact-hole (C/H)
patterns were also successfully fabricated under annular illumination (σ=0.3/0.5). Due to astigmatic aberration, the C/H
patterns were deformed at defocused positions, but they were almost circular at the best focus position. The flare of the
projection optics measured by the Kirk method was 11% over a flare range of 1-100 μm. The effects of the 11% flare
were evaluated using dark- and bright-field 32-nm L&S patterns. It was found that the top loss and line-width roughness
(LWR) of the resist were larger for bright-field than for dark-field patterns. To reduce the impact of flare, we need EUV
resists that are more robust with regard to flare. A comparison of the measured point spread function (PSF) of the flare
and the calculated PSF revealed good agreement for long-range flare but some difference for short-range flare.

Effects of aberration and flare on lithographic performance of SFET

When a thinner absorber mask is applied to extreme ultraviolet (EUV) lithography for chip production, it becomes essential to a introduce light-shield border in order to suppress the leakage of EUV light from the adjacent exposure shots. In this paper, we evaluate the leakage of both EUV and out-of-band from light-shield border and clarify the dependence of lithographic performance on light-shield border structure using a small field exposure tool with/without spectral purify filter (SPF). Then we evaluate the lithographic performance of a thin absorber EUV mask with light-shield border of the etched multilayer type and demonstrate the merit of its structure using a full-field scanner operating under the currently employed condition of EUV source in which SPF is not installed.

Light-shield border impact on the printability of extreme-ultraviolet mask

PROBLEM TO BE SOLVED: To provide a microfabrication apparatus capable of suppressing a reduction in the throughput in manufacturing a device using a nano-imprint technology SOLUTION: The microfabrication apparatus is provided with: a first measuring means 7 for pressing an original plate 1 including a pattern to a substrate to be transferred 3 to transfer the pattern to the substrate to be transferred 3 and measuring the relative positional displacement between the substrate to be transferred 3 and the original plate 1; a position correcting means 9 for correcting the relative position between the original plate 1 and the substrate to be transferred 3 in such a manner as to transfer the pattern to the predetermined position of the substrate to be transferred 3 on the basis of the positional displacement measured by the first measuring means 7; a pressing means for pressing the original plate 1 to the substrate to be transferred 3 in such a state that the relative position between the original plate 1 and the substrate to be transferred 3 is corrected by the position correcting means 9; and a second measuring means 20 for measuring the relative positional relation between the pattern transferred to the substrate to be transferred 3 and the pattern that is pre-formed on the substrate to be transferred 3 COPYRIGHT: (C)2009,JPO&INPIT

Kazuo Tawarayama

Papers

Extreme Ultraviolet Lithography Using Small-Field Exposure Tool: Current Status

Aberration measurement from specific photolithographic images: a different approach

Effects of aberration and flare on lithographic performance of SFET

Light-shield border impact on the printability of extreme-ultraviolet mask

Microfabrication apparatus and method of manufacturing device