Methods and technologies / Synthesis and processing | Research Center for Electronic and Optical Materials

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Methods and technologies
Synthesis and processing

The technologies used at this center can be broadly divided into synthesis/manufacturing technology and evaluation analysis technology.
This page specifically focuses on Synthesis and processing methods. Method for Characterization and measurements is at 【another page 】.

There is also a wide range of Synthesis and processing technologies. First, it is a means of obtaining the desired material by reacting or melting substances at high temperatures, using a so-called "furnace. " On the other hand, it is a means of synthesizing materials at relatively low temperatures, that is, using chemical methods that can be imaged from beakers or flasks. It provides a means of synthesizing substances from liquids such as aqueous solutions. There are also processes that use liquids and do not involve a dissolution step. An example of this is the process of dispersing powder into a liquid. Dispersion processes are of great importance in materials synthesis.

Another method is to synthesize materials by depositing vaporized raw materials as solids on a substrate. This process of precipitating a solid phase from a gas phase is often used for high-purity synthesis in a vacuum environment. Furthermore, this center will utilize shape forming technology such as microfabrication technology for device formation.
We also have equipment available for use by outside organizations. If you are interested, please inquire.

【Characterization and measurements】 page

Solid and melt processes / high temperature processes
We will introduce manufacturing processes that use high temperatures, such as solid phase reactions and melt processes, at this center.

Bulk single crystal growth

It is a process that produces large single crystals from melted liquid at high temperatures.

Production of large, high-quality single crystals for optical applications using the pulling method

Group in charge
Optical Single Crystals Group

SHIMAMURA, Kiyoshi VILLORA, Garcia Equipment List

CTAS piezoelectric crystal. A transparent, pale yellow single crystal on a ruler, fan-shaped to ~90mm. Stable large growth. Color variations of LiREF4 crystals. Five crystals aligned by a ruler. Colors: Tb (clear), Dy (yellow), Ho (red), Er (pink), and Yb (clear).

Single crystal growth using Bridgman method etc

Group in charge
Optical Single Crystals Group

NAKAMURA, MasaruEquipment List

Bridgman crystal. A bullet-shaped, 4cm metallic ingot with a mirror-like luster, indicating high ordered structure & purity.

Sintering

This is the process of creating ceramics by densifying powder at high temperatures.

Fabrication of transparent ceramics using sintering technology

Group in charge
Optical Ceramics Group

SUZUKI, Tohru

Group in charge
Polycrystalline Optical Material Group

MORITA, Koji

Transparent ceramics. Left: Spinel disc reveals text underneath. Right: 1μm SEM of alumina layer on a spinel matrix.

High temperature gas reaction

This is a synthesis method that involves reacting a solid at high temperature with a gas. A typical example is nitride synthesis using ammonia.

Synthesis of nitrides and oxynitrides through high-temperature reactions

Group in charge
Advanced Phosphor Group

TAKEDA, Takashi

Group in charge
Electro-ceramics Group

SUEHIRO, Takayuki

Group in charge
Amorphous Material Group

SEGAWA, Hiroyo

Nitride morphologies. Left: 1μm SEM of dense spherical particles. Right: 10μm SEM of intersecting fibers.

We would like to introduce the liquid phase process at this center.

Colloid process

This is a process for controlling the behavior of fine particles dispersed in a liquid to bring out material properties.

Ceramic particle orientation control using field

Group in charge
Optical Ceramics Group

SUZUKI, Tohru

Magnetic orientation. Top: Apparatus & conductivity graph. Bottom: Transmittance graph. Samples show higher clarity via alignment.

Production of photonic colloid sheets from suspensions

Group in charge
Nanophotonics Group

FUDOUZI, Hiroshi

Photonic sheets. Left: Precision coating system. Right: Large sheet showing structural color gradient from green to blue.

Precipitation from solution

Solid-phase materials are synthesized by precipitating raw materials dissolved in a solvent.

Precipitation of nanoparticles with controlled particle shape from solution

Group in charge
Electro-ceramics Group

SAITO, Noriko

TEM: Pyramidal ZnO particles (50nm scale). Right: Resistivity graph showing 0.5% Au-loaded ZnO has high Isoprene sensitivity.

Hydrothermal synthesis method: Crystal precipitation from aqueous solution in critical state

Group in charge
Optical Ceramics Group

NAKANE, Takayuki

Sol-gel method

Group in charge
Amorphous Material Group

SEGAWA, Hiroyo HAYASE, Gen

Electrochemical synthesis method

A synthesis method that induces chemical reactions and mass transport by applying an electric field to the interface between a solution and a solid.

Formation of film by anodic oxidation of metal

Group in charge
Amorphous Material Group

SEGAWA, Hiroyo

Anodic alumina films. 6 plates show a color transition from gray to yellow. Structural color via nanoscale thickness control.

We will introduce vapor phase growth at this center.

Molecular beam epitaxy (MBE)

This is a process in which raw materials are vaporized in a vacuum and then deposited and crystallized on a wafer.

Crystal growth of nitride semiconductors

Group in charge
Amorphous Material Group

OGAKI, Takeshi

Chemical vapor deposition (CVD)

This is a process in which raw material molecules carried by a gas flow react on the substrate surface and precipitate and crystallize.

Hydride vapor phase epitaxy (HVPE)

This is a crystal growth method in which raw metal is transported onto a substrate as chloride gas and crystals are deposited on the substrate.

Group in charge
Ultra-wide Bandgap Semiconductors Group

OSHIMA, Yuichi

Schematic of Ga2O3 HVPE system & growth rate graph vs GaCl. Bottom: SEM images of 150μm crystal & 5μm hexagonal pillars.

Pulsed laser deposition (PLD)

This is a thin film growth process in which raw materials evaporated by laser pulse irradiation are deposited and crystallized on a substrate wafer.

Formation of semiconductor thin films and dielectric thin films by PLD method

Group in charge
Electro-ceramics Group

ADACHI, YutakaSHIMIZU, TakaoOHSAWA, Takeo

Group in charge
Nano Electronics Device Materials Group

NAGATA, TakahiroEquipment List

Atomic control. Left: 3nm model of LaAlO3 on SrTiO3. Right: 1nm atomic resolution STEM showing a sharp interface.

sputtering deposition

Raw materials vaporized using plasma are deposited on a wafer to grow crystals and synthesize thin film crystals.

Formation of semiconductor thin films and dielectric thin films by sputtering method

Group in charge
Electro-ceramics Group

SHIMIZU, TakaoOHSAWA, Takeo

Group in charge
Nano Electronics Device Materials Group

NAGATA, TakahiroEquipment List

Combinatorial Physical Vapor Deposition

Composition-gradient thin-film sample fabrication by by combining a movable mask and a control system with a multi-source physical vapor deposition method.

Combinatorial Thin-Film Synthesis System

Group in charge
Nano Electronics Device Materials Group

NAGATA, TakahiroEquipment List

Fabrication processes used in this center

Lithography

It is a process in which fine structures are formed on the surface of a wafer or thin film using pattern formation on a resist film using electron beams or light.

Formation of metamaterials by lithography

Group in charge
Nanophotonics Group

IWANAGA, Masanobu

Group in charge
Semiconductor Epitaxial Structures Group

MIYAZAKI, HidekiEquipment List

Metamaterial sensor. Top: Au/Quantum well for photocurrent. Bottom: Resonance mode, 1μm SEM & 5mm packaged device.

Formation of waveguide type nonlinear optical element by lithography

Group in charge
Quantum Photonics Group

KURIMURA, Sunao

Phase matching types. Top: Periodic waveguide. Table: Type 0 has d33=25pm/V (Eff=1). Types I/II have d=5 (Eff=1/25).

Fabrication of Electronic and Photonic Devices via Lithography

Group in chargeSemiconductor Epitaxial Structures Group
MANO, TakaakiIMURA, MasatakaHAYASHI, YusukeEquipment List

Etching

This method uses acid/alkaline solutions, plasma, etc. to remove the sample surface by dissolving or evaporating it and giving it the desired shape.

Fabricating metamaterials using lithography

Group in charge
Ultra-wide Bandgap Semiconductors Group

OSHIMA, Takayoshi

Group in charge
Nanophotonics Group

IWANAGA, Masanobu

SEM: Non-plasma selective growth/etching of fins & trenches. Right: 50μm scale fin-type transistor with terminals.

Strong magnetic field application

By applying a magnetic field to powder, etc., particle aggregation and orientation are controlled.

Particle motion control using magnetic fields

Group in charge
Optical Ceramics Group

HIROTA, NoriyukiSUZUKI, Tohru

Magnetic alignment. Fine black particles in liquid form vertical needle-like chains under a magnetic field for ceramics.
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