This paper describes the view of the CMP (chemical-mechanical polishing) technology corresponding to Cu

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The surface roughness and profile of the polishing pad that comes in contact mechanically with the silicon wafer are thought to be one of the important factors that influence the polishing result in the polishing process of the silicon wafer for which super flatness is needed by a big diameter wafer manufacturing. Whether the surface roughness and profile of the polishing pad exerted any influence on polishing the silicon wafer in this research was verified by the polishing simulation, and it worked on the research on the domination of the surface treatment processing of the polishing pad.

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Recently, the role of pad is very important in particular Cu-CMP process.
In addition, it is very important to understand the combination between mechanical factor and chemical components of slurry.
More specifically, the potential impact of the mechanical and chemical properties as well as the physical construction of the pad such grooving pattern of the pad is studied. It is important to understand the impact of physical design and chemical properties of the pad on its ability to transport, host, and possibly react to the spent slurry that could be significantly different from the original formulation. One of such study is to elucidate the source of defects such as edge over erosion.
The possibility to improve the edge over erosion with non-cell type pad is reported here.

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In the last paper, it checked the combination of an LHA pad and an oxidizer raising a polishing rate in polishing of a single-crystal SiC, and making the surface roughness of a polishing side fine.In this paper, the influence of polishing on a single-crystal SiC was investigated about TiO2 as a candidate of the oxidization catalyst which can carry out intension in a polishing pad.Consequently, it became clear that a polishing rate was raised in the quantity of 10w% of a silica abrasive-grain.

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[in Japanese]

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Cu and barrier slurry for 45nm and 32nm technology node were developed. Key for next generation slurry is to reduce the

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In Chemical Mechanical Polishing (CMP) process, the ″Post CMP cleaning″ that remove slurry residue and polishing waste on the wafer is a very important technology. This is because their result directly controls the yield of the process productive ability. In this report, we will propose a new post-CMP cleaning method utilizing high pressure micro jet (HPMJ) system and run evaluation experiments using substrates with polystyrene latex (PSL) particles adhered on their surface. Results indicate that higher the pressure is and shorter the stand off distance was, the removal rate of PSL on substrates were higher. In addition, the smaller the diameter of the PSL particle is, the removal rate were lower.

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When HPMJ (high pressure micro-jet) is in use, static electricity is generated. In this study, main causes of such generation have been analyzed, leading to the study of basic characteristics of generating static electricity by using the faraday cage designed by the authors to measure the static electricity. As a result, it has been clarified that the generation of static electricity can be controlled by lowering specific resistance of deionized water. This finding provided a prospect that by using CO2 water or ionized alkali water, generation of static electricity can be prevented or reduced.

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Polishing experiments are carried out in the present research in order to verify an analytical model for a simulation of Chemical Mechanical Polishing (CMP) process. A three-dimensional finite element analysis of CMP process, which considers the boundary lubrication between a wafer and a polishing pad, is utilized to predict a friction resistance. Additionally, the friction forces are measured in the polishing experiments by force sensors built into the experimental setup. It is conformed that the predictions of friction resistance directions fit experimental results. These results indicate that the friction resistance direction depends on the ratio of the wafer to the polishing pad rotation speeds.

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Various technical problems on fabrication have to be solved to achieve performance demanded with a semiconductor device

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[in Japanese]

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The circulation of industrial materials has been important on environmentally friendly. The study focuses on the tungsten chemical mechanical polishing slurry recycle technique. We found that zeta potential of the slurry was low by effect the tungsten included. The zeta potential measured as check item of recycled slurry.

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We investigated glass polishing mechanism with ceria slurry by modifying mechanical and chemical conditions, and found chemical conditions were related to polishing performance. In this study we applied this chemical modifying to fixed abrasive polishing, and investigated polishing performance.

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MEMS technology is regarded as one of the most promising technologies for the next generation industries. However initial

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The ultraviolet-ray irradiating type polisher was fabricated for accomplishing a polishing experiment of copper. This paper describes the polishing characteristics of copper by almina and titania. The polishing speed increased and the surface rouness decreased by irradiating ultraviolet ray. However, the polishing characteristics are different in both grains. These depend on the exciting properties of fluorescent substances, grains and copper.

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We reported a damage-free planarization of 4H-SiC (0001) wafers using a new planarization technique we called CAtalyst-Referred Etching (CARE) in previous research. The CARE setup equipped with a polishing pad made of a platinum (Pt) catalyst is almost the same as a lapping setup. Since the catalyst generates a reactive species that activate only when it is next to the catalyst surface, SiC can be chemically removed when in contact with the catalyst surface with a pressure noticeably lower than that in a conventional polishing process. Pt is, however, an expensive material thus we have to find alternative catalyst for low-cost SiC surface finishing. In this research, we show the ability of molybdenum (Mo) instead of Pt for SiC planarization in CARE process. Optical interferometry images show that a surface polished with a Mo plate is equal in quality to that of one polished using Pt.

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[in Japanese]

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This paper does the proposal of appropriate measuring method on the surface texture. This study uses scanning white light interferometry and light lever system. The object material is a plastic, the size is 1 mm x1 mm x0.1 mm, and groove depth of the texture are 3 ㎛. Consequently, according to the schedule at first, light lever system is the range of motion of the piezo element narrow, accordingly the entire measurement is impossible. Scanning white light interferometry measures by generating the interference stripe, as a result, measurement of the entire texture is possible.

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[in Japanese]

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Silicon carbide (SiC) is a wide-band-gap compound semiconductor. The purpose of this study is to prepare a clean and flat 4H-SiC(0001) surface with crystallinity, and evaluate the surface structure at an atomic level. Atomic force microscopy (AFM) observations reveal that the 4H-SiC(0001) surface is composed of steps and terraces, when it is treated by a novel polishing process with a platinum catalyst in HF solutions. Scanning tunneling microscopy(STM) observations demonstrate that this surface is formed by a 1x1 phase with other superstructures. We analyze the surface formation mechanism during the wet-chemical preparations by X-ray photoelectron spectroscopy (XPS) measurements.

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A lot of high speed and high precision machine tools has been developed in these days. The key technologies are high

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[in Japanese]

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[in Japanese]

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The prototype of a desktop machine tool with ion-control capability has been developed in this study. This small size machine tool can change machining liquid resistance automatically by ion-controlling. In this paper, the specifications and functions of the machine tool are introduced. In order to apply to the machine tool, complex machining process that is combination of electrical and mechanical processes is developed. 16μm width groove is machined by a complex machining process combining ECM and cutting.

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In the motion error of parallel kinematic mechanism machine tool, the elastic deformation caused by external force such as the gravity is a significant factor as same as the kinematic parameter error. The deformation error increases in case that a spindle head is inclined largely, and unable to be ignored with a long cutting tool. In this paper, we model the deformation error with statics and rigidities of the mechanical components, and present a compensation system, in which the position and posture of the spindle head is compensated by the actuator commands with the predicted deformation error. This system realizes improving the motion accuracy of the machine.

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As the factors in motion errors of parallel kinematic mechanism, there are kinematics parameter errors and elastic deformation caused by the gravity. Furthermore, in case that resistance of passive joints cannot be ignored, internal force generated by the joint resistance deforms the mechanical components. Therefore, in order to realize high accuracy motion control, it is necessary to analyze the influence of the joints resistance in the mechanism components.
In this paper, we propose the analysis model that describes the influence of the passive joints resistance in the mechanism components. The validity of the proposed method is proved by experiments.

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To easily improve the bending rigidity of the tool holder made of steel in the higher range of spindle speed, a spindle model was newly proposed having an alumina ceramics ring set up around the periphery of the spindle edge. The characteristics of the model were examined by numerical simulations with FEM comparing the results of a steel spindle model and an alumina ceramics one. In the proposed model, the bending rigidity of the tool holder, which was little affected by the spindle speed, was slightly smaller than that in the alumina ceramics model and was larger in the higher range of spindle speed than that in the steel model. The contact state on the shank of the tool holder in the proposed model resulted in the larger axial displacement, which was smaller than that in the steel model, in comparison with that in the alumina ceramics model.

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A new enlargement mechanism of the PZT displacement has been developed. The static and dynamic characteristics are evaluated. The 4 times of the enlargement of the PZT is obtained by the developed device.
The non-circle cutting is realized by adopting this mechanism to the cutting holder. The profile accuracy settles in 3 micrometer.

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A machine tool is developed to manufacture micro-scale parts in cutting. The machine tool has 5 axes driven by stepping motors with high resolution. The machine tool has a table controlled by the linear motions of X- and Y- axis and the rotational motion of A- and C- axis; and a spindle with the cutting tool controlled by Z-axis. The machining processes can be controlled by a personal computer. Some cutting tests are performed to verify the design and the efficiency in micro machining on the developed machine tool.

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The purpose of this study is acquired the machining load from machine tools possible of micro machining of the several tens μm level. As a result, tool breakage prevention and machining condition can be calculated. By the regression analysis which was one of the data mining techniques from machining load concretely acquired, permission machining load is predicted for the feed rate. And, the surface roughness was able to be controlled of the every machining condition by the relationship between machining load and surface roughness.

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[in Japanese]

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Recently, high speed and high precision machining has been required. One of the basic performances of a high precision machining is motion accuracy in high speed and small radius circular motion. In this paper, circular motion accuracy of a high precision machining center with linear motor drives and hydrostatic guideways which are friction less is measured and evaluated. When elliptic error is evaluated by radius ratio and phase difference between X-axis and Y-axis, radius ratio and phase difference can be expressed as a quintic function of angular speed.

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A new real-time inverse transfer function method is proposed to achieve rapid and precise positioning of an NC table. The calculated transfer functions during motion are assumed as the second-order lag system. The parameters of dynamic characteristics are identified in real-time, considering changes of the parameters by piecewise linearization of motion. Nonlinear characteristics are considered consequently in the parameters by this operation. The compensated input calculated by the identified parameters is fed into the NC driver in real-time. To evaluate the effectiveness of the proposed method, we machined the work piece by the circular interpolation and measured the contoured profile. The contoured profile of circularity showed the considerable reduction.

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The purpose of this research is to develop hi-speed and hi-accuracy machining system which is corresponded to 1 micron of accuracy. The servo data is the set of position command at every servo cycle time, which is minimum unit of position command in NC machining processes. The servo data is directly generated by geometric model interpolation without NC program. And motion errors are simulated and compensated automatically. This report refers to the result of machining experiment by adapting the geometric model interpolation and compensation of motion error.

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Laser beam machining has many excellent machining properties as compared to the other machining

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Drilling of mono-crystalline silicon by laser beam delivered through optical fiber to the working point in etchant. Mixture of KOH and H2O2 was chosen as etchant and 0.5mm thick silicon was used as a workpiece. When CW Ar-ion laser was irradiated at 10W, silicon was drilled at a speed of about 40µm/min. On the other hand, when pulsed Nd:YLF laser was used, processing rate became higher and was about 600µm/min. Moreover a hole deeper than 3mm was obtained.

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We studied an effect of SF6 assist gas on process quality of silicon wafer laser processing. Applying SF6 gas was observed dramatically reduces debris adherence around a groove edge. Ablation plasma emission intensity during processing was measured by spectroscope to realize a relation between a defocused-distance and low debris adherence conditions. These studies showed a low debris adherence point was formed in a vicinity of a focal point where intense plasma formed.

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Material removal cannot be generated by low power density laser beam. However, plumes are generated from the heated area. In the present study, the heated region is sealed so that high pressure is generated inside the sealed region.This causes molten metal removal. As a result, a hole can be drilled in 1 mm thick stainless steel by 10⁵ W/cm ²laser beam, which is usually operated for welding.

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When short and high power laser pulse is irradiated on a solid surface under water, very high stress is induced by confinement effect of plasma. Here we report about the confinement effect in laser irradiation under liquids which is observed by an imaging system with nanosecond time resolution. The system uses 1064nm of a Q-switched Nd:YAG laser as a processing laser and 532nm of another Nd:YAG laser as illuminating light. When the laser pulse is irradiated under liquid film, higher stress waves, which occur at the material surface and propagated into the bulk, than those in air are observed by both shadow graph and photoelasticity images. Even if a laser is irradiated thorough a drop of water on the sample surface, high stress occurs. When paraffin is used, strong stress waves occur, too. However, the stress is estimated to be lower than water. Thin layer of liquid less than 1 mm is enough to induce the confinement effects.

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A femtosecond laser is a promising tool in precise micromachining with little heat affected zone. In patterning metal electrodes of an organic light emitting diode, a femtosecond fiber laser has been used and its potential in the process has been demonstrated. Machinability of the metal electrode, however, shows strange dependences on the structure of the machined part: aluminum(Al) thin film deposited on thin Indium tin oxide(ITO) layer is machined by lower energy pulses than that deposited directly on glass substrate. The threshold energy of removal of films with different compositions, namely Al on glass, Al on ITO on glass and ITO on glass, is determined. Attempts of observing the machining processed for these films have been carried out.

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A microneedle made of biodegradable polymer material (Poly lactic acid, called as PLA) is fabricated by micromolding method, and a hole of high aspect ratio (diameter 10um, length 1mm) is fabricated on this needle by using an excimer laser beam. A phenomenon is observed that the inside of hole is clogged at several points by ablated material and outing gases. Same laser fabrication is preformed on other polymer materials of Parylene, PDMS (Polydimethylsiloxane), Epoxy, Nylon, PMMA (Polymethylmethacrylate), PC (Polycarbonate), PS (Polystyrene), however, this phenomenon of clogging is not observed, which indicates this phenomenon is peculiar to PLA material.

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Recently, the demand to the diffractive optical elements is increasing with the developments in the microfabrication technology. In this research, we created the diffractive optical elements with the use of the Laser Direct Write Lithography System that has the feature of high-resolution drawing, high-speed drawing, and a high accuracy positioning system. Although it is difficult to draw to a large-sized substrate with electron-beam lithography system, since the Direct Write Laser Lithography System makes it possible, production of the large-sized diffractive optical elements is expected. Furthermore, 2 and 4 levels phase-type diffraction optical elements were produced by wet etching processing to the substrate, and comparison of the diffraction efficiency of the amplitude-type diffractive optical element and the phase-type diffractive optical element was discussed.

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To create a future system of extreme-ultraviolet (EUV) lithography, an innovative light source with 13.5nm wavelength is demanded very high power and long operation life at high repetition rate. Tin target has significant potential for high conversion efficiency (CE). We have proposed a new method to develop high performance EUV light source by using the tin target with cone shape. We investigate the EUV emission from high density plasma produced by focused laser to Sn targets, using a photo diode sensor with Mo/Si filter. We measure the angular distribution of EUV emission and evaluate the CE for our proposed tin targets with conical hole.

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A SWNT′s (Single Wall Carbon Nanotubes) paper was used for a lithium ion secondary battery as an electrode. A SWNT′s electrode surface was modified by laser ablation to improve charge-discharge characteristics and to suppress a SEI formation of a lithium ion secondary battery. Charge-discharge measurements results showed that modified SWNT electrodes have high reversible capacities as compare to no modified SWNT electrode.

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We considered creating a micro fluidic device into a fluoro resin using an excimer laser process. Through holes as artificial capillary-vessels are made in the resin having a minimum diameter of 5 μm and a length of 100 μm by laser ablation. And micro-channels are fabricated on the periphery of the holes by the same process. A number of resin-films are piled up on a soda glass. A laser fabricates a part of the channel at each film on every film, and then 3-D microchannel are fabricated. We experimented on running blood into the groove and the vessels for blood test.

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We fabricated micro-fluidic device for blood tests by laser in a laminate film on a glass substrate. We use two lasers property, excimer laser and Nd:YAG laser were used for study of how to fabricate the micro-fluidic device. Using this method, we succeeded in creating a three-pronged micro-fluidic device to study blood cells lined up in a row formation. We also succeeded in fabricating an artificial capillary-vessel micro-fluidic device to observe the erythrocyte deformability. The dimension of these chips is around 10mm square, but a blood pumping unit is above 100mm square. Therefore, we contrived an on-chip pump unit by the principle of the sandglass. In this paper, we considered creating a micro-fluidic device that is composed of one blood reservoir, two physiological-salt solution reservoirs, and the three-pronged groove. Moreover, following the three-pronged groove, the artificial capillary-vessels are added in a same chip. We also experimented on running blood into the groove and the vessels for blood test.

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The authors proposed a method of laser machining with absorbent slurry for micromachining in glass material. Nanoparticles of ZnO, TiO2 and CeO2 were investigated as absorbent. Some experiments were conducted to make a comparison among these absorbent nanoparticles. In the experiments, the grooves on silica glass and the holes in silica glass were machined by UV laser (355nm) with absorbent slurry. By examining the depths of the grooves, the depths of the holes and the roughness of the wall of the holes, the optimum nanoparticles were determined for micromachining in silica glass.

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Thermal stress cleaving is a prospective technique for separating a wafer or thin plate from brittle materials such as glasses and ceramics. In this paper, the cleaving mechanism of a glass and a sapphire irradiated with CO₂ laser is investigated. A high frequency pulsed laser is used for the purpose of investigating the mechanism of crack propagation more precisely. The AE signal is measured to examine the characteristics of crack propagation. Thermal damage to the surface of the glass causes the deterioration of cleaving accuracy. Consequently, it is important to minimize the thermal damage by controlling the prosess parameters.

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In the laser cleaving process with a thermal stress induced by a diode laser scanning, a surface groove is introduced as an initial defect which is a begining point of crack propagation. In this study, the principal properties and characteristics of the method presented are investigated.

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In order to perform micro-nano fabrication with high accuracy, it is important to smooth the surface.
In this research, the sputtering phenomenon arising from the ion beam was applied for smoothing of surface of the material.
Ar1 + beam was irradiated on tungsten carbide with changing the incident angle.
To derive the roughness of surface, the surface of irradiated WC was observed by AFM.
The relation between the incident angle and the roughness will be shown.

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