A common photodetecting unit detects a plurality of beams scanned by a plurality of polyhedral reflection mirrors provided in a multiple stages with a common rotation axis, and generates a synchronization detection signal based on detected beams. The reflection mirrors make a predetermined angle θ1 in a direction of rotation of the reflection mirrors. When time between two consecutive synchronization detection signals on a time line generated by the common photodetecting unit is ti, where i is a positive integer equal to or smaller than number of split beams, at least one of ti is different from others.

Optical scanning device and image forming apparatus

A method for identifying lithographically significant defects. A photomask is illuminated to produce images that experience different parameters of the reticle as imaged by an inspection tool. Example parameters include a transmission intensity image and a reflection intensity image. The images are processed together to recover a band limited mask pattern associated with the photomask. A model of an exposure lithography system for chip fabrication is adapted to accommodate the band limited mask pattern as an input which is input into the model to obtain an aerial image of the mask pattern that is processed with a photoresist model yielding a resist-modeled image. The resist-modeled image is used to determine if the photomask has lithographically significant defects.

Method for detecting lithographically significant defects on reticles

A method of manipulating a focused light beam includes focusing a beam of excitation light with a lens to a focal spot within a sample, where a cross-section of the beam includes individual beamlets. Directions and/or relative phases of the individual beamlets of the excitation beam at a rear pupil of the lens are individually varied with a wavefront modulating element, and emission light emitted from the focal spot is detected while the directions or relative phases of individual beamlets are varied. The directions of individual beamlets are controlled to either maximize or minimize the emission light from the focal spot, and the relative phases of individual beamlets are controlled to increase the emission light from the focal spot.

Microscopy with adaptive optics

In an optical information reading apparatus, a pickup unit has a predetermined reading position, and is configured to optically pickup information of a target when the information is located at the reading position. A marker beam irradiating unit includes a light beam source configured to emit a light beam. The marker beam irradiating unit includes a beam pattern forming lens arranged to allow the emitted light beam to enter thereinto. The pattern forming lens is configured to irradiate a marker beam based on the emitted light beam. The marker beam has a predetermined beam pattern composed of at least one linear beamlet to indicate the reading position of the pickup unit.

Optical information reading apparatus

EUV lithography is expected to be not only for hp 2Xnm node device production method but also for hp 1X nm
node. We have already developed the mask inspection system using 199nm wavelength with simultaneous transmitted
and reflected illumination optics, which utilize p-polarized and s-polarized illumination for high defect detection
sensitivity, and we developed a new image contrast enhancement method which changes the digitizing rate of imaging
sensor depending on the signal level. Also, we evaluate the mask structure which improve the image contrast and defect
detection sensitivity. EUVL-mask has different configuration from transmitted type optical-mask. A captured image
simulator has been developed to study the polarized illumination performance theoretically of our inspection system.
Preferable mask structure for defect detection and possibility of miss defect detection are considered.

Study of EUV mask inspection technique using DUV light source for hp22nm and beyond

The usage of ArF immersion lithography for hp 65nm node and beyond leads to the increase of mask error enhancement factor in the exposure process. Wavelength of inspection tool is required to consistent with wavelength of lithography tool. Wavelength consistency becomes more important by the introduction of phase shift mask such as Tri-tone mask and alternating phase shift mask. Therefore, mask inspection system, whose inspection light wavelength is 199nm, has been developed. This system has transmission and reflection inspection mode, and throughput, using 70 nm pixel size, were designed within 2hours per mask. The experimental results show expected advantages for Die-to-Die and Die-to-Database inspection compared with the system using 257nm inspection optics. Shorter wavelength effect makes transmission inspection sensitivity increase, and realizes 40nm size particle inspection. As for the phase shift mask, the difference of gray value between the area with phase defect and without phase defect was clear relatively. In this paper, specifications and design, experimental results are described.

Development of advanced reticle inspection apparatus for hp 65 nm node device and beyond

We have developed a mask inspection system using 199nm inspection light wavelength. This system performs 
transmission and reflection inspection processes concurrently within two hours per plate. By the evaluation result of 
mask images and inspection sensitivity, it is confirmed that the 199nm inspection system has the advantage over the 
system using 257nm and has the possibility corresponding to next generation mask inspection. Furthermore, advanced 
die-to-database (D-DB) inspection, which can generate high-fidelity of a reference image based on the CAD data for 
alternating phase shift mask (PSM) or tri-tone, is required for next generation inspection system, too. Therefore, a 
reference image generation method using two-layer CAD data has been developed. In this paper, the effectiveness of 
this method is described.

Development of next-generation mask inspection method by using the feature of mask image captured with 199-nm inspection optics

PROBLEM TO BE SOLVED: To provide a reticle inspection device capable of two-dimensional correction. SOLUTION: This device is characterized by being equipped with an X-axis laser interferometer 201 and an X-axis laser scale 202 for measuring an X-coordinate position on a reticle 101; a Y-axis laser interferometer 211 and a Y-axis laser scale 212 for measuring a Y-coordinate position on the reticle 101; a laser optical device 103 and a transmitted light detection part 105 or the like used as an optical image acquisition part for acquiring an optical image on the reticle 101; an optical image correction part 140 for correcting the position of the optical image acquired by the optical image acquisition part based on XY-coordinates in a design of a plurality of prescribed positions on the reticle 101 and XY-coordinates of the plurality of prescribed positions measured by the X-axis laser interferometer 201 and the X-axis laser scale 202, and the Y-axis laser interferometer 211 and the Y-axis laser scale 212; and an image comparison part 108 for comparing the optical image with a prescribed reference image on the corrected position. COPYRIGHT: (C)2007,JPO&INPIT

Sample inspection device and sample inspection method

An optical inspection apparatus for inspecting an inspection target surface by irradiating the inspection target surface with light, includes: a condensing and scanning optical system for condensing light from a light source on the inspection target surface in a minute spot shape and scanning the condensed minute-spot-shaped light onto the inspection target surface; and a phase change information detection apparatus for detecting optical phase change information in an area of the inspection target surface irradiated with the minute-spot-shaped light scanned by the condensing and scanning optical system.

Optical inspection apparatus and optical inspection method

We have improved DUV laser reticle inspection system LM7000 for 90 nm technology node devices. To increase inspection sensitivity, we developed a reflected light inspection as a supplementary method to transmittance light inspection. We have also strengthened inspection algorithm to distinguish between real defects and very small features from optical proximity effect correction (OPC). Finally, we have improved reference image for die to database inspection. With the merit of short wavelength of LM7000 (266 nm), the inspection sensitivity of the high-transmittance half-tone phase shift mask (HTPSM) does not deteriorated so severely compared to that of binary mask. With the help of these series of improvements, LM7000 could shows inspection capability for OPC masks and HTPSM for ArF lithography. The inspection capability of LM7000 was proved with the programmed defect masks and printability experiment using ArF scanner.

Motonari Tateno

Papers

Development of advanced reticle inspection apparatus for hp 65 nm node device and beyond

Development of next-generation mask inspection method by using the feature of mask image captured with 199-nm inspection optics

Sample inspection device and sample inspection method

Optical inspection apparatus and optical inspection method

Inspection capability of high-transmittance HTPSM and OPC masks for ArF lithography