Effectively preventing the reattachment of nano-particles on the substrate surface is indispensable in the wafer cleaning process. In this paper, we attempted to track the three-dimensional behavior of sub-100 nm particles in shear flow and elucidate the reattachment phenomenon by using a combined observation method that uses evanescent light field and dark field observation methods in the same field of view and extends the measurement of particle height position from the observed surface from several hundred nm to several um.

In power device polishing, long polishing times are required to remove the damaged layer that occurs on the surface during the previous processing step, so it is important to manage the damaged layer. Conventionally used measurement methods generally involve measurements using a microscope, etc., but there are issues such as having to stop the machining process and requiring time for measurement. In this study, we are working on a measurement method that focuses on electrical resistance as a method for monitoring the amount of damaged layer in a short period of time. We will introduce the current situation.

Diamond is a typical difficult machining material due to its exceptional hardness, stiffness, and chemical inertness. However, the Plasma-Assisted Polishing (PAP) process has shown significant potential for diamond surface finishing, enabling a remarkable material removal rate (MRR) and achieving ultra-smooth surfaces. In this study, we conducted a comprehensive comparison between traditional silica polishing plates and silicon polishing plates for diamond substrate surface finishing. The results demonstrated that silicon polishing plates outperformed silica polishing plates in both MRR and surface roughness, highlighting their superior performance for diamond surface finishing applications.

There are still challenges in the GaN manufacturing process in terms of cost, time, and environmental impact. In this study, we attempted experiments to determine whether processing could be performed using only the friction of a buff, without the use of abrasives. The results showed that removal processing is possible using a PVA buff. This presentation will provide a detailed report on these findings.

We are continuing our investigation of highly efficient processing of GaN substrates with UV irradiation, oxidants, and pH adjustment. In this study, we used suede polishers with different hole arrangements while keeping the total amount of UV light transmission constant, and evaluated the effect of time variation in the UV activation zone for different UV irradiation methods on the polishing processing speed of GaN substrates.

GaN and SiC are chemically stable, hard, and brittle materials, and research into processing and polishing methods is being actively conducted. In this study, the GaN surface was processed using a diamond probe in air using the nanoscratching method at loads of 0.5 to 30 mN, and the surface was observed using AFM and the damage layer inside the crystal was observed using TEM. At a load of 0.5 mN, the processing depth was about 7.0 nm, but a damage layer of about 230 nm was observed below the processed area. The results of the SiC evaluation will be reported at a conference.

We have been conducting a basic study of the polishing process using the microscopic tip of an AFM stylus as an abrasive grain. In this report, we investigate the scratch processing characteristics of GaN, which is currently considered to be an important next-generation power device but is difficult to process, by comparing it with SiC, Si, and quartz, which are also brittle materials.

This paper presents studies on the creation of surface functions by utilizing the interaction of light with the microstructure of material surfaces. A method for fabricating metal nanodot arrays on quartz glass substrates by a combination of microfabrication and heat treatment will be described. The application of gold nanodot arrays to biosensors and surface-enhanced Raman scattering (SERS) substrates will also be discussed. In addition, the possibility of metamaterials and optical trapping will be discussed.

This research aims to develop a nanopore device for the analysis of viruses and microparticles. The nanopore device is a device in which two chambers with electrodes are connected by a microscopic flow channel, and analysis is performed using the change in electric current caused by microparticles passing through the channel. In order to improve the accuracy of the analysis, we have applied the Bayesian optimization method and the particle swarm optimization method to the electromagnetic finite element method to determine the electrode structure in the chamber to obtain the optimal electric field distribution.

A mold for nano-order slanted diffraction gratings as optical elements for AR/MR is fabricated by electron beam exposure and oblique dry etching. In this study, a slanted diffraction grating was directly fabricated on the resist by irradiating the electron beam obliquely. As a result of the experiment, the shape of the slanted diffraction grating was improved by PEB, so this time we will report it.

CO2 laser processing is widely used for processing blind via holes (BVH) on printed wiring boards (PWBs). PWBs are composite materials, and it is difficult to ensure processing quality. In addition, it is not possible to observe the internal state of the processed BVHs from the outside. The quality inspection relies on destructive inspection by sampling, which is very costly. In this paper, we investigated the ejecta particles generated during processing to develop a new monitoring method.