KEYWORDS: Cameras, Imaging systems, 3D image processing, Digital cameras, 3D metrology, 3D displays, Projection systems, Image processing, Binary data, Modulators
An automatic three-dimensional shape measurement system using an optical spatial modulator and robot arm has been
proposed. The system is composed of an optical spatial modulator from which grating patterns are projected on the
surface of the object, a digital camera controlled by a robot arm, and a computer. The patterns on the surface of the
object were taken into the computer by the digital camera, and the 3D coordinate of the surface of the object was
calculated by modified 3D coordinate conversion equations. The three dimensional shape was measured without any
contact in short time in the system. The system was improved using mechanical and optical method and data analysis by
modified program. Using zoom lens in the camera, the measurement accuracy and range were improved by using correct
proofreading factor per camera pixel and reasonable threshold setting. In this modified system, proofreading factor per
camera pixel are measured as a zooming factor, therefore this system don't need to use camera factor and is convenient
system.
A technique for morphology control of self-assembled organic films based on laser ablation is presented. The
regioregular poly 3-hexylthiophene (RR-P3HT) films prepared by using drop casting method and spin coating method
are irradiated and ablated by the ultraviolet KrF excimer laser. Absorption spectra and XRD profiles of the films are
investigated. For spin coated films, Blue absorption spectral shift is observed; For drop cast films, Blue shift in the
absorption spectra, accompanied with the disappearance of the peak intensity of XRD profiles, are observed. The results
indicate that molecular structure has been changed due to photo-thermal effect and molecule cutting effect of laser
ablation.
An automatic three-dimensional whole circumference shapes measurement system using an optical patterns projection
technique has been developed. The system is composed of an optical spatial modulator from which grating patterns are
projected on the surface of the object set on a turntable stage, a CCD camera controlled by a robot arm, and a computer.
The patterns on the surface of the object are taken into the computer by the CCD camera, and the three-dimensional
coordinates of the patterns on the surface of the object are calculated according to a principle of a trigonometry
measurement. The patterns faced to the CCD camera are taken into the computer by the CCD camera, four photographs
at each turntable angle of 0, 90, 180, and 270 degrees are processed and the image processing data are composed as
whole circumference shapes. This improved system using mechanical and optical method and data analysis has the
following advantages. (1) It is possible to capture the surface topography without any contact. (2) The time required for
the measurements is shorter than the light-section method. (3) The optical spatial modulator using a liquid crystal
projector enables to control the striped patterns accurately by the computer. (4) It is possible to measure precisely and to
expand the measurement area using a zoom camera. (5) The improved system has whole circumference shapes
measurement area as well as high resolution.
In this paper, pentacene and metalphthalocyanine was deposited on polycarbonate (PC) thin film using vacuum deposition and their morphologies and molecular orientations were investigated using X-ray Diffraction (XRD) spectrometer and UV/Vis spectrometer. From these results, pentacene and metalphthalocyanine molecules were concluded to be perpendicular on the PC film. The organic field effect transistor (OFET) with pentacene thin film or copperphthalocyanine thin film as an active layer and PC thin film as a gate dielectric film was fabricated on the polyethylene naphtalate (PEN) film (substrate). The drain current versus drain voltage characteristics of the OFET were measured.
The morphologies and nonlinear optical properties of vanadylphthalocyanine (VOPc) thin films on polymer and KBr substrates remain unclear. This paper investigates the morphologies and nonlinear optical properties of VOPc thin films prepared on polycarbonate (PC) and KBr substrates by UV/Vis spectrum measured with UV/Vis spectroscopy, X-ray diffraction (XRD) and third-order harmonics (TH), as well as second-order harmonics (SH) detected using the Maker fringe method. The UV/Vis spectra of VOPc thin films prepared on a PC substrate with different evaporating source temperatures have a peak at 840 nm in the Q-band region. This indicates that the morphology of the VOPc thin films prepared is Phase II. Moreover, the UV/Vis spectra of each sample do not change with increasing thickness. Therefore, this also suggests that interaction between a VOPc molecule and the surface of a polycarbonate film is strong. The number of VOPc molecules oriented at 60° to a substrate markedly increases with the increase in evaporating source temperature. This indicates that there is an optimum evaporating source temperature for the orientation of VOPc thin films prepared on a PC substrate. In VOPc thin films prepared on a KBr substrate, the phase morphology of VOPc thin films changes from pseudoepitaxy to epitaxy by increasing the annealing time. Moreover, the incident angle dependence of second harmonic (SH) intensity shows a lower convex curve when irradiated with a p-polarized laser light, and the SH intensity is enhanced with the increase of the annealing time. Moreover, the incident angle dependence of third harmonic (TH) intensity shows upper convex curves and the maximum values of TH intensity are enhanced with the increase of the annealing time. These findings indicate that the orientation of VOPc thin films is improved with the increase in annealing time. It is closely related to molecular diffusion during annealing.
An automatic measurement system of three-dimensional shapes by a projection method with striped patterns from an optical spatial modulator has been developed. Patterns on the surface of the object were taken into a computer by a CCD camera, and the 3D cocordinate of the surface of the object was calculated according to a principle of a trigonometry measurement. This system has the following advantages. (1) It is possible to capture the surface topography without any contact. (2) The time required for the measurements is shorter than the light-section method. (3) The optical spatial modulator using a liquid crystal projector is possible to control the striped patterns accurately by the computer. (4) It is possible to measure precisely and to expand the measurement area using a zoom camera. In this study, we developed the method with using zooming of a CCD camera image. By using zooming of a CCD camera image, the measurement accuracy improved and the measurement range was expandable.
Vanadyl-phthlocyanine (VOPc) thin films were prepared by a molecular beam epitaxy on a polyimide (PI) substrate at 150°C, and then they were exposed to dichloroethane vapor for 25 hours. Their morphologies were investigated with Vis/UV spectra and the surface images observed by an atomic force microscope (AFM). The Vis/UV spectrum of VOPc thin film before the organic gas treatment has a broad absorption shoulder between 640 and 740nm and an absorption
peak at 840nm in the Q band region. It has been known so far that VOPc thin film has Phase I ,II and III. Phase I has two absorption peaks at 680 and 740nm. Phase II and Phase III are characterized with absorption peaks at 820 and 830nm, respectively. Therefore, the morphology having an absorption peak at 840nm is different from that of Phase 111 . The Vis/UV spectrum of VOPc thin film after the organic gas treatment has a broad absorption shoulder between 640 and 740nm and an absorption peak at 830nm in the Q band region. The absorption peak at 840nm shifts to 830nm by the organic gas treatment. This means that the phase morphology of VOPc thin film changes into Phase III during the gas treatment. On the other hand, VOPc molecules deposited on P1 substrate before the organic gas treatment form needle crystals. This indicates that VOPc molecules deposited on P1 substrate are perpendicular to PI substrate. The surface image of VOPc thin film after the gas treatment is smooth. This suggests that VOPc molecules are parallel to PI substrate. The third-order optical susceptibilities after and before the gas treatment are 3.75x10-9 and 3.25x10-9 esu, respectively. The molecular orientation of VOPc thin film is improved during the organic gas treatment.
We have continued research on the three-dimensional shape measurement system, using spatial projections. This method is non-contact, non-invasive, and completes measurement in a short time. However, light diffusion influence on the measurable accuracy. In addition, if marking on the surface of target object, it will become difficult to perform exact measurement. And the sampling density is not fully high. We proposed methods using differentiation and light variation patterns to enhance accuracy of measurement, to eliminate the influence of marking on the surface of target object, and to increase the sampling density. Since our methods involve computational manipulation of the data obtained by the original system, it requires no additional equipment. It is a very practical and effective method.
Vanadyl-phthalaocyanine (VOPc) films were prepared on KCI substrate by a molecular beam epitaxy (MBE) method. The SEM image revealed that a VOPc single crystal of 120)mumX120)mum grew on the KCI substrate after annealiing for 360 minutes. Its average film thickness was about 110 nm. The growth of single crystal was assisted by the surface diffusion of VOPc molecules and the difference in chemical potential between single crystals. Therefore, the single crystal grows merging neighboring grains and/or VOPc molecules surrounding. The VIS/UV spectrum of single crystal had the absorption peaks at 700nm and 860nm and also the absorption shoulder at 640nm. The maximum absorption peak is at 860nm. According to Griffiths et al., the phase having peaks at 680nm and 740nm is called Phase I and the phases having a main absorption peaks at 820nm and 830nm are called Phase II and Phase III, respectively. Phases having a main absorption peaks at 780nm and 810nm are called Pseudomorphic layer and epitaxial growth, respectively. As mentioned above, the phase having a main absorption peak at 860nm has not been reported so far. We call it Phase IV. The VOPc film having Phase IV shows a third harmonic (TH) generation. The TH susceptibility is larger by about 103 times than that of quartz glass. This indicates that Phase IV has high molecular packing density and good nonlinear optical properties. Therefore the single crystal on KCI substrate prepared by MBE is expected to apply to optical switching, modulation and memory (RAM and ROM).
In this paper, the VOPc film was prepared on KBr substrate by OMBD. After that, it was treated in organic gas. The thickness of VOPc film was 96 nm. The morphologies of VOPc film before and after the gas treatment were characterized with optical absorption spectra and SEM image. The third- harmonic generation of VOPc film before and after the gas treatment were also measured by Maker fringe method using a Nd:YAG laser.
Some types of rough alignment system for pre-alignment of precise alignment is proposed. One is a system using wide pitch gratings, with narrow pitch gratings for precise alignment. The other is a system using only narrow pitch gratings with small slit number, which is simple in construction. The operations are discussed on the basis of the results of computer simulation.
We have continued research on our 3D shape measurement system, using spatial projections of light variation patterns. This method is non-contact, non-invasive, and completes measurement in a short time. However, light diffusion influence on the measurable accuracy. We proposed a method using differentiation to enhance accuracy of measurement, and were successful in achieving this goal. Moreover, the measurable area was expanded. Since our method involves computational manipulation of the data obtained by the original system, it requires no additional equipment. It is a very practical and effective method.
PMMA and PET thin films doped with (t-Bu)4VOPc {(t- Bu)4VOPc PMMA and (t-Bu)4VOPc PET} and PMMA thin film doped with (t-bu)1. 4VOPc {(t-Bu)1. 4 VOPc PMMA} were prepared on glass substrate by coating (t-Bu)4VOPc PMMA and (t-Bu)4VOPcPET were treated with dichloroethane vapor in a desiccator at room temperature. On the other hand, (t-Bu)1. 4VOPc PMMA was treated with dichloroethane and chloroform vapor in the desiccator at room temperature. The (t-Bu)1. 4VOPc PMMA and (t-Bu)4VOPc PMMA thin films showed SHG and THG after vapor treatment but (t-Bu)4VOPc PET thin film did not. These suggest that the degree of swelling by dichloroethane vapor are different between PMMA and PET. In other words, the aggregation of (t-Bu4) VOPc occurs more easily in PMMA than in PET. The THG of (t-Bu)1. 4VOPc PMMA thin film is larger than that of a (t-Bu)4VOPc PMMA thin film. This means that the molecular size of (t-Bu)1. 4VOPc is smaller than that of the size of (t-Bu)4VOPc.
A kinetic model for a discharge-pumped ArF excimer laser has been developed. The electrical circuit loss, collision loss of electrons and atoms in plasma, and photon absorption loss were calculated. The energy loss process from the electrical input to the laser output is discussed. It was found that 34% of the electrical input is lost in the electrical circuit, 30% of the deposited energy is lost as a elastic collision loss. Since there are large quenching losses and photo absorptions, the laser output energy is several percent of the input energy.
An ablation wave from materials based on laser supported detonation and laser supported combustion has been created by exposing them with laser. The purpose of this study is to analyse the mechanism of the ablation wave using a high speed streaked camera and to realize more precise microprocessing by controlling the wave. The laser used in this experiment was an ultraviolet XeCl excimer laser of high photon energy with a wavelength of 308nm, a maximum pulse energy of 500mJ, a pulse width of 30ns and a maximum frequency of 50Hz. The high speed streaked camera had a resolving power of 100ps. Metal-ceramics functionally graded materials (FGMs) were selected as sample materials. An experimental system of laser microprocessing was constructed and the behavior of the ablation wave from FGMs were observed. The experimental results showed that the mechanism of the ablation wave from FGMs was a photochemical reaction with thermal interaction.
This paper presents an automatic, accurate mask aligner based on modified moire technique. In this technique the alignment marks are in the form of gratings. The high slope region of moire signal is used to obtain higher sensitivity and better position control accuracy. Automatic alignment is achieved by using difference of moire signal and its inverted signal obtained by computer. Accuracy for alignment, under the present experimental conditions, is of the order of +/- 0.06 micrometers . Our alignment technique by virtue of its higher alignment accuracy is suitable to X-ray lithography. However, due to nonavailability of a X- ray source the lithography was performed by UV source. Nevertheless, the effort is worth it so as to prove the workability of this technique. The overlay accuracy is estimated to be 0.8 micrometers which is limited by the diffraction effects of the exposure optics.
Moire technique with different variations has been successfully used for mask alignment, with very high accuracies. In this paper we report a new approach to computer controlled mask alignment using modified moire technique. In this technique alignment is controlled in the higher slope region of the moire signal using a single pair of grating alignment marks. In the present case a phase shifted signal is generated by the computer using the input moire signal. The point at which this phase shifted signal becomes equal to the moire signal is treated as the alignment point. The error signal for controlling alignment is obtained by computing the difference of instantaneous moire signal from the intensity of this point. Computer simulation studies as well as experimental studies were conducted on this approach. The results of these studies are presented.
This paper deals with an autoiatic and precision alignient technique for
proxiiity printing in x-ray lithography, using two pairs of iioire gratings,
with moire signals from each pair being 180 out of phase with each other.
The automatic and precision alignment experimental system which was
constructed can measure both transmission moire signals and reflection moire
signals at the same time. The automatic alignment was achieved using
diffracted moire signals in transmission and also in reflection as control
signals for a stage driver. The alignient position of the system was
monitored by the difference signal in non-control signals. The drift
characteristics of the alignment position were measured by operating voltage
gain and/or offset voltage value of preamplifiers in the system. We concluded
that the technique using diffracted moire signals is a usable automatic and
precision alignment technique and the technique could be applied to one of
the variable positioning techniques.
Projection moire alignment is a highly useful technique for mix and match lithographic system. The
same alignment marks are used for both photo and X-ray photolithography and high sensitivity is
obtained using simple alignment optics. This paper deals with a projection moire alignment system
which applies to a g-line or i-line stepper that is part of a mix and match lithographic system. A He-Ne
laser is used as the light for alignment. By using two pairs of gratings which are 1/2 grating pitch out of
phase with each other, we obtain two moire signals which are also 1/2 grating pitch out of phase. Using
difference of these two moire signals, high sensitivity is obtained. In order to achieve high overlay
accuracy in automatic alignment, it is important to consider the shape of the alignment marks.
Asymmetrical resist coverage caused by spin coating causes an offset error and in case of aluminum
coated wafers, a rough surface causes a random error. Some defects in the gratings caused during
etching process also produce error. For the purpose of analyzing some effects of alignment marks on
projection moire alignment, we calculated alignment error using Fresnel diffraction integral. We obtained
the following results. An aberration method using reflected light from wafer marks is useful for rough
surfaces. Defects in a grating are eliminated by average effects. And we calculated an alignment error
caused by wafer tilt. By tilting 5 second to 10 second, output waves become asymmetry and contrast is
reduced. Tilt of 5 sec. makes an alignment error of about 0.03 tm.
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