森田 昇

It is known that a high performance micro system for the medical treatment, biotechnology, and nanotechnology etc, become a system where the electric circuit and the sensor are integrated on flat surface and spherical surface etc. In the future, anisotropic etching for spherical single-crystal silicon can be a key technique in order to develop a higher performance micro system. This paper has investigated the result of microstructure fabrication in spherical single-crystal silicon by anisotropic etching, and proposed a selection indicator in the line direction of mask pattern (crystal orientation), which is corresponded to users.

Copyright © 2017 SPIE. The 3D nano-machining and measuring system that can control with nanometer-scale accuracy have been developed in this research. In this system, the functions of position control and NC have been expanded based on surface observation function of friction force microscope (FFM). Precision positioning of cantilever was possible by using the displacement sensor in this system. Newly machining cantilever1with high stiffness was developed, and spinous single diamond grain was bonded on the end of this cantilever. Cantilevers for machining and measuring were able to exchange alternately. By using this system, 3D nano-machining and measuring was achieved.

The research that micro-machining of the square on the surface (100) of single crystal silicon by the machining cantilever installed in friction force microscope is presented in this paper. It was found that the machined area is changed into striking convex after the work piece is etched by KOH solution. The relation that the height of the convex depends on the machining conditions especially on the concentration of KOH solution is understood. In order to understand the contrary etching results, the structure of machined surface was analyzed by TEM(transmitting electronic microscope) and Laser Raman Method, The result that thick oxidation and beneath deterioration exisited in the surface was showed. Moreover, the efficiency of ultrasonic cleaning combined with etching to improve the roughness and removing of the remained is confirmed. And the method of maskless formation of micro-structure as the application of the experimental results is proposed.

Nano-machining experiments are necessary in order to quantitatively understand the nano-machining process. A unique nano-machining and measurement FFM system, which has a stiff cantilever for processing, has been developed. The system can machine hard material with the removal bit size of 1 - 100 nm. The experimental results revealed two key characteristics of nano-machining. Firstly, the shape of the trace varies because of the irregularity of the tip shape and the wear of the cutting edge. Secondly, the depth of the trace processed by using area scanning is about 10 times as large as that by linear scanning. To explain this, a model of the processing was proposed, in which the removal efficiency is raised by feeding the scanning line. Measurements of variations of the horizontal forces and the shape of the cutting chips verified the model.

Neither the processing phenomenon nor the rule factor of nano-scale cutting is not still enough understood. It is an important problem to understand them in order to establish the processing technologies of minute parts. In this paper, the result of nano-scale cutting of single crystal silicon by using friction force microscope is described. The (100) surface of single crystal silicon was etched by KOH solution after nano-scale cutting of 15 μ m X 15 μ m area. It was found the etch rate was extremely different between the cut area and non-cut area. The cut area remained as it was little being etched. Dependence of remaining height on normal cutting force and cutting velocity and KOH solution concentration was examined. The new processing technique of micro-structure was proposed by applying the above-mentioned experiment result.

The final goal of this research is to construct a laser processing system to manufacture stepped shapes or free-form surfaces using the information of detected laser processing sound. In order to achieve this goal, basic investigations concerning the analysis of the characteristics of laser processing sound are necessary. The purpose of this report is focused on the analysis of the frequency characteristics of a detected sound of a single pulse laser beam, and to clarify those of a continuous pulse laser beam by calculation.

A radiation of the electron called exoelectron from the machined surface is observed with less energy than usual work function, and it is known that this phenomenon is sensible to changes of crystal structure and surface structure. This paper describes the result of examining the possibility of photo stimulated exoelectron emission as a method of the process monitoring and surface evaluation. As a result of cutting experiment in vacuum atmosphere, it is confirmed that electron emission is observed during the distruction of materials and that there is a relationship between cutting conditions and emission behavior on the machined surface. These results show the possibility of exoelectron emission for new method of process monitoring and surface evaluation.

Laser processing is an important manufacturing technology in machining difficult-to-cut materials. It is known that a sound is generated when laser processing is carried out, the intensity of the sound changing according to the processing conditions. The purpose of this research is to clarify experimentally the relationship between the material removal characteristics and the pressure level of the processing sound when a low and a high frequency laser beam are applied to the processing of ceramic materials. (C) 2000 Elsevier Science S.A. All rights reserved.

A nanometer scale machining system using the mechanism of a friction force microscope was developed to machine hard materials such as metal and glass. While performing experiments to observe chemical action during nanometer scale machining, we found a phenomenon in which the affected layer on the machined area of single-crystal silicon had a masking effect on anisotropic etching by KOH solution. As the result, the machined area remained, and a square pillar structure was formed. This paper reports on the method used and describes an example. The mechanism of the phenomenon is discussed with the identification data of the affected layer using laser Raman spectroscopy and transmission electron microscopy.

This report describes molecular dyn, amics simulations of tensile tests of single crystal pure iron. There are a few experimental data of plastic region tensile tests of pure iron. In this simulation, strain range are elastic and plastic region, and to fracture point and temperature conditions are 100K to 1100K. In this report, different three kinds of models of tensile directions ([00l], [011] and [111]) are used. They are axis of rotational symmetry of bcc-type crystals. In the simulation results, stress-strain diagrams are important. They are different from polycrystal iron's in macro-scale. The stress-strain diagrams differ from tensile directions and temperatures. In tensile tests of [001] and [011] directions, we find second elastic regions after plastic regions. In second elastic regions, crystal structure types are changed from bcc-type. We find two types of structure phase trasitions.

The goal of the research is to construct a laser processing system for the manufacture of stepped shapes. In order to achieve this goal, this study aims to clarify the relationship between the strength of laser processing sound and groove cross-sectional area per pulse when a Q-switched YAG laser beam was applied for laser grooving. The main findings of this study are as follows: 1) The relationship between the strength of the processing sound and groove cross-sectional area per pulse of Q-switched laser beam could be expressed by a straight line on a log-log chart even if the applied laser energies were changed, and 2) The gradient of the straight line showed different values when two types of work materials were processed by a Q-switched YAG laser.

The micro-indentation and micro-scratch device is newly developed for trial purposes aiming to evaluate the mechanical characteristic of the material surface layer by a precision machining or a micro-processing. The device enables us to precisely measure an indentation load-depth curve, and to determine the micro-hardness, the micro-scratch hardness and friction coefficient of a subsurface damaged layer and a thin film layer of lum or less with the same equipment. It is found that the depth profile of the micro-hardness chatacterizes the thickness of a stress hardening layer of a diamond cutting surface, and that the friction coefficient of a mono-crystal silicon is different from a silicon oxide thin film.

This paper describes the mechanism of brittle-ductile transition of monocrystal silicon at a high temperature and its feasibility for ductile mode cutting. The micro-cutting tests were carried out at various temperatures, and for various cutting speeds and depth of cut by using a newly developed cutting device. The critical depth of cut is closely related to the material temperature and cutting speed. When the material temperature is 973 K at a cutting speed of 1 mm/s, the critical depth of cut is about two times that at room temperature. The critical depth of cut decreases with increasing in cutting speed. The specific cutting force is nearly constant at various temperatures. The residual stress on the ductile-mode cutting surface is compressive about 200 MPa.

In order to clear the behavior of material deformation and fracture during machining the hard and brittle materials such as a glass, the indentation tests have been carried out in various environment. The results of the experiments showed that the crack length and velocity of crack propagation, depends on a percent relation humidity in the environment, and on the stress of the surface of glass, and increases with increasing the percent relation humidity in the environment. The experimental data also showed that the dependence of crack length and velocity of crack propagation on humidity will be stronger with increases applied load. Experimental results are discussed in this paper. © 1998, The Japan Society of Mechanical Engineers. All rights reserved.

A high-resolution scanning phase-measuring acoustic microscope was used to investigate the near-surface residual stress distribution in mono-crystal silicon and pure aluminum. The 4-point bending device was newly developed and used to measure an acoustic velocity applied stress curve for the materials. The stress dependence of acoustic velocity was presented and compared with a theoretical result. Image of the stress field at the diamond ductile cutting surface of monocrystal silicon was observed. The stress distribution by the acoustic method was much the same as that by the micro-1aser Raman method. It was found that the acoustic velocity in pure aluminum at the prastic deformation field was non-1inear and satulated.

In order to control the process of the nanometer scale machining precisely, it is necessary to understand the change of mechanism in nanometer-scale removing process. In this point of view, a unique nano-machining and measurement system, which utilizes the mechanisms of FFM, has been newly developed for the purpose of observation on nano-machining in the scale from 1 to 100 nm. The system has both an original micro–cantilever for machining and an ordinary micro cantilever for AFM measurement, and it also has a device which can exchange two cantilevers alternatively. To evaluate the performance of the system, a single crystal silicon was machined and scratched by a single diamond grain which was fixed on the end of the cantilever. Then, the system could make 2 μ m x 2 μm square holes of 70 nm in maximum depth. Moreover it also could make scratches obviously and measure the lateral reaction force at a time. Those results proved the system effective in nano-machining experiments. © 1998, The Japan Society of Mechanical Engineers. All rights reserved.

The results of basic experimental study on cryogenic machining of hard and brittle materials are presented in this paper. In order to understand the basic phenomenon of material deformation and fractue during machining the hard and brittle materials such as a glass and a semiconductor at low temperature, the indentation tests and single point diamond scratching tests have been carried out. The results of tests showed that the crack length and the indentation depth decreases, the hardness and the critical depth of brittle-ductile transition increases with the decrease of material temperature for both soda-lime glass and single crystal silicon. The optical microscope observations showed that the deformation behavior and cracking patterns at low temperature are different from those at room temperature. From our experiments, we can conclude that the cryogenic machining is advantageous to restrain generation and propagation of cracks during machining the hard and brittle materials. © 1998, The Japan Society of Mechanical Engineers. All rights reserved.

The effects of temperatures on the stress evaluation of boron doped silicon in solid and film forms are investigated. Several techniques, such as fluid cooling to eliminate the temperature raise and/or simultaneous observation of Stokes and anti Stokes peaks to compensate the temperature effects, are applied. The advantages and disadvantages of each method and the abilities and limits of these techniques are discussed.

The purpose of this paper is to understand the behaviors of formation and fracture during grinding of hard-brittle materials,and to clear the effects of atmosphere and machining conditions on surface characteristic.As above purpose, the indentation, single point scratching with diamond Vickers indenter and grinding experiments were carried out at various atmosphere for soda-lime glass.The dependence of crack length, the depth of brittle ductile transition and state of ground surface on atmosphere are discussed. The results of indentation for soda-lime glass indicated that a crack length not only depends on indentation load,specimen temperature etc. but also depends on indenting environment, and the crack length due to indentation in oil is shorter than one in air or water.The results of single point scratching experiment showed that the depth of brittle ductile transition carried out in vegetable oil is larger than that in others.The results of grinding experiments showed that the state of ground surface depends on atmosphere strongly, and the roughness of surface ground with vegetable oil is better than others.According to above results, we shall give the advice which is that an atmosphere like low humidity and good lubricity is very effective for high integrity grinding of glass.