Nanografi Nanotechnology

Float-Zone Silicon (FZ-Si) wafers are the high purity and newer alternative to to Czochralski (CZ-Si) wafers. These wafers have high temperature capabilities and a low concentration of light impurities, such as carbon and oxygen, which can be prevalent in Czochralski (CZ-Si), are extremely low with FZ-Si wafers. However, Float-Zone silicon’s (FZ-Si) mechanical strength can be improved by deliberately adding nitrogen to it in the growth process, which also helps to control microdefects. Float-Zone silicon (FZ-Si) wafers are generally, not greater than hundred and fifty millimeters. That is due to surface tension effects during the growth process. Float-Zone silicon’s (FZ-Si) impurity enables it to undergo a lighter doping process. In some cases, Float-Zone silicon produce high resistivity measurements that reach high heights. Float-zone silicon is obtained by the Float-Zone (FZ) method, based in the vertical zone-melting principle that was invented by Theuerer in 1962 at Bell Lab

Gallium arsenide (GaAs) is a compound of the elements gallium and arsenic. These two elements combine and form III-V semiconductor with a zinc blende crystal structure. Gallium Arsenide (GaAs) is one of the most important compound semiconductor materials in the world- it is widely used in many applications in wireless, opto-electronics, and Solar Cells. Gallium arsenide (GaAs) can be supplied as ingots or ingot sections or as cut, etched or polished wafers and are individually laser scribed with ingot and slice identity. Gallium arsenide (GaAs) wafers possess a combination of superior properties such as high electron mobility, direct band gap, high conversion efficiency, and high frequency with less noise. Three methods can prepare gallium arsenide: the vertical gradient freeze (VGF), the Bridgman-Stockbarger technique and liquid encapsulated Czochralski (LEC) growth. ­The most common process for producing GaAs wafers is The VGF technique. This method differs from any other grow

Quartz is highly pure and therefore has high working and melting temperatures. Quartz wafers possess many unique features such as high anti corrosion, high optical transmittance, low dielectric loss, good thermal conductivity and high working temperature. Quartz’s cross-linked three-dimensional structure delivers exceptional UV transparency, thermal shock resistance, and near-zero thermal expansion. Quartz, due to its purity, thermal and optical properties is superior to those of other glass materials. Quartz is perfect for semiconductor fabrication and laboratory equipment. Quartz monocrystals are produced with hydrothermal synthesis process. High quality broken pieces of quartz are placed at the bottom of the vessel filled with NaOH. Quartz crystallizes at a temperature of approx. 400°C and a pressure of 1000 - 1500 bar from a saturated NaOH solution at quartz seed crystals that have a lower temperature than the crushed source quartz at the bottom of the container. Quartz growth

Fused Silica Wafers are thin, circular pieces of UV fused silica originally designed for the use as test substrates to measure the quality of optical coatings. Fused Silica also sometimes called “Fused Quartz” is the amorphous phase (glassy form) of quartz (SiO2) and is thus isotropic. It is tough and hard and has a very low expansion. It has no additives, unlike e.g. borosilicate glass, thus is pure SiO2. Fused silica has higher transmission in the ultraviolet and infrared spectrum, a superior chemical resistance and high dielectric strength, a very low thermal expansion coefficient and a high softening point and high thermal resistance. Standard thicknesses of fused silica wafers are 500, 700 and 1000 μm with diameters of 2, 3, 4 and 6 inches. Production process of fused silica mainly consists of the method of melting and re-solidifying of ultrapure SiO2. Silicon-rich chemical precursors such as SiCl4 are used for synthesis of fused silica by the process of gasifying and oxidizi

The main insulating material used in micro-technology is Silicon Dioxide, which in chemical symbols is written as SiO2. In semiconductor technology, SiO2 thin film layers are mainly used as dielectric material film in transistors, capacitors (DRAM) or flash-memories. Silicon Oxide Wafers are produced using crystallization, solid state and other ultra-high purification processes such as sublimation. This process forms a cylindrical ingot, which is then sliced and polished to form wafers. Thermal oxide is a kind of "grown" oxide layer, compared to CVD deposited oxide layer, it has a higher uniformity, and higher dielectric strength, it is an excellent dielectric layer as an insulator . In most silicon- based devices, thermal oxide layer play an important role to pacify the silicon surface to act as doping barriers and as surface dielectrics. The simplest way to produce an insulating silicon oxide layers (SiO2) on silicon wafers is to oxidize silicon with oxygen, which

Monocrystalline silicon (mono-Si) grown by the Czochralski process is often referred to as monocrystalline Czochralski silicon (CZ-Si). CZ-Si higher speed of production, low cost, higher resistance to thermal stress and the high oxygen concentration that offers the possibility of Internal Gettering made it the most commercially grown silicon. The CZ-Si wafers are produced with a method of crystal growth used to obtain single crystals of semiconductors e.g. palladium, platinum, silver, gold and many oxide crystals. The 99% of all semiconductor devices are made of monocrystalline silicon. Because of the large dependency, users have on technological devices crystal silicon is a tremendously important part of modern world. Due to the importance of the wafer’s purity, the process of growing crystalline materials is very important. There are several different methods of growing necessary crystals for silicon wafers. One of the methods used for growing this crystalline material used in s

Carbon nanofibers (CNFs) are long, fibrous carbon layers of a platelet type - perpendicularly arranged individual layers to the fiber axis or of herringbone type - nested inside one another at an angle. The arrangement is determined depending on the catalyst used Carbon nanofibers (CNFs) are in a class of one-dimensional carbonaceous materials with exceptional electronic conductivity, which made them a perfect use as conductive additives in electrode materials for lithium-ion batteries and sodium-ion batteries. When Carbon nanofibers (CNFs) are used explicitly as anode materials for production of numerous intercalation sites, they show excellent performance of sodium and lithium storage. For non-carbon electrodes of lithium-ion & sodium-ion, Carbon nanofibers (CNFs) can function as electron conducting and porous substrates enhancing the overall electronic & ionic conductivity alongside with stabilization of the electrode structures during cycling, causing the improvement o

Cellulose is a linear biopolymer naturally found in plant cells like wood and cotton and is the main building block of trees and plants. It is considered the most abundant polymer in nature and possesses many unique characteristics such as good biocompatibility, low cost, low density, and exceptional mechanical properties. Nanocellulose nanocrystals organization is structured of densely ordered crystalline particles engineered by nature in a way that makes it inherently strong. The cellulose fibers can be converted into cellulose nanofibers (CNFs) or cellulose nanocrystals (CNCs) after mechanical or chemical treatments. They show outstanding characteristics when compared not only to the original cellulosic fiber but also to other materials typically used as reinforcements in composite materials e.g. “Kevlar” or steel wires. Cellulose nanocrystals (CNCs) possess some several notable chemical, electrical and optical properties: ­The size, shape and charge of cellulose nanocrysta

Gallium is a soft silvery-white metal, inert and nontoxic; it possesses characteristics different to those of other metals. It is liquid at near room temperature, and brittle solid at lower temperatures. Gallium is one of four metals -- mercury, cesium, and rubidium that can be used in high-temperature thermometers. Gallium may be cooled to 0 °C without solidifying, and is denser as a liquid than as a solid. It has a high tendency to supercool below its freezing point. Moreover, gallium has one of the longest liquid ranges of any metal and even at high temperatures; it has a low vapor pressure. Soluble in acid, alkali and slightly soluble in mercury. High-purity gallium is attacked slowly only by mineral acids. Melting point: 29.76 °C Boiling point: 2204 °C Density: 5.904 gm/cc Thermal Conductivity: 0.281 W/cm/K @ 302.93 K Electrical Resistivity: 17.4 microhm-cm @ 20 oC Electronegativity: 1.6 Originally discovered in 1875, gallium, at the time, was primarily used to ma

Silicon Nitride Coating - stoichiometric trisilicon tetranitride (Si3N4) thanks to its very high mechanical and thermal stability is used for tools such as roller bearings used under harsh conditions. In the semiconductor industry, silicon nitride layers are used as dielectric material, passivation layers or can act as hardmask mask. Silicon Nitride has good high temperature strength, creep resistance and oxidation resistance. Silicon Nitride's low thermal expansion coefficient gives good thermal shock resistance. Silicon Nitride is produced in three main types; Reaction Bonded Silicon Nitride (RBSN), Hot Pressed Silicon Nitride (HPSN) and Sintered Silicon Nitride (SSN). There are two main depositions of silicon nitride layers: LPCVD Silicon Nitride – Low pressure chemical vapor deposition silicon nitride. LPCVD silicon nitride layers are easily deposited on silicon wafers in a reproducible, pure and uniform way. This leads to silicon nitride layers with low electrical condu

Erbium oxide (Er 2 O 3 ) is the compound in the oxide form of the rare earth metal erbium. Erbium oxide is also known as erbia and erbium trioxide. Erbium oxide has a pink color. The cubic crystal structure is the structure that erbium oxide has. However, under certain conditions erbium oxide could have a hexagonal structure. Erbium oxide is not soluble in water, with a high melting point at temperature of 2344 o C. Hence, this erbium oxide compound is said to be well heat endurable and chemically durable under high temperatures. Erbium oxide films have a high dielectric constant. At room temperature erbium oxide is strongly photo luminescent compound. Erbium oxide has been used in variety of applications like microelectronic, optoelectronic, thermophotovoltaic and biomedical applications. Erbium oxide is even used in nuclear reactors. Erbium oxide is used as colorant for glasses Erbium oxide is used as burnable poison for nuclear fuel Erbium oxide is used in the protection

Europium oxide(Eu 2 O 3 ) is an oxide of rare earth metal europium. Europium oxide has also other names as Europia, Europium trioxide and Dieuropium trioxide. Europium oxide has a pinkish white color. Europium oxide has two different structures: cubic and monoclinic. The cubic structured europium oxide is almost same as magnesium oxide structure. Europium oxide has negligible solubility in water, but readily dissolves in mineral acids. Europium oxide is thermally stable material that has melting point at 2350  o C. Europium oxide’s multi-efficient properties like magnetic, optical and luminescence properties make this material very important. Europium oxide has an ability to absorb moisture and carbon dioxide in atmosphere. Europium oxide has a great potential as photoactive materials for the photocatalytic degradation of organic pollutants. Europium oxide nanoparticles is used in magnetic resonance imaging since europium oxide is clinically relevant and frequently applied contras

Gadolinium oxide (Gd 2 O 3 ) compound is the oxide form of one of the rare earth metal gadolinium. Gadolinium oxide is also known as gadolinium sesquioxide, gadolinium trioxide and Gadolinia. The color of the gadolinium oxide is white. Gadolinium oxide is odorless, not soluble in water, but soluble in acids. Gadolinium oxide could be appeared in three different structures: cubic (c-Gd 2 O 3 ), monoclinic (m-Gd 2 O 3 ) and hexagonal (h-Gd 2 O 3 ). The cubic gadolinium oxide changes to monoclinic structure at 1200 o C. While the hexagonal gadolinium oxide phase exists above melting point which is at temperature of 2420 o C. Gadolinium oxide is the most available form of the pure gadolinium. Gadolinium oxide has physiochemical properties like the crystallographic stability up 2325 o C, high mechanical strength, excellent thermal conductivity, and a wide band optical band. The gadolinium oxides has a variety of applications. Gadolinium oxide is used in magnetic resonance and fluores

Holmium oxide (Ho 2 O 3 ) is the oxide form of the rare earth metal holmium. Holmium oxide is also known as holmia and holmium sesquioxide. This holmium oxide compound occurs in nature. Mostly, holmium oxide are contained in minerals like gadolinite and monazite. Holmium oxide has light yellow-orange, pale-yellow and beige colors. Holmium oxide is not soluble in water, but soluble in acids. The cubic structure is the only structure for holmium oxide compound. Holmium oxide has a melting point at temperature of 2415 o C. Holmium oxides has a few applications. Holmium oxide is used as colorants for glasses and cubic zirconia Holmium oxide is used as a specialty catalyst, phosphor and laser material Holmium oxide is used in ceramics, glasses, phosphorous, and metal halides lamps Holmium oxide is used in nuclear reactors to control the atomic chain reaction Holmium oxide is used as calibration standard for optical spectrophotometers since holmium oxide solutions have sharp o

Lanthanum oxide (La 2 O 3 ) compound is the oxide form compound of the lanthanide metal lanthanum. Lanthanum oxide is also known as lanthana and lanthanum sesquioxide. Lanthanum oxide has a white color. Lanthanum oxide is not soluble in water, but readily dissolves in dilute mineral acids. The hexagonal crystal structure is the structure in which lanthanum oxide exists at low temperature. But at high temperatures lanthanum oxide may have a cubic crystal structure. Lanthanum oxide starts to melt at temperature of 2315 o C, and lanthanum oxide has a boiling point at a high temperature of 4200 o C. Due to its ability to absorb carbon dioxide and moisture, lanthanum oxide becomes lanthanum carbonate and lanthanum hydroxide, respectively, in the presence of air. Lanthanum oxide has a variety of applications. Lanthanum oxide is used in the manufacturing of optical glasses to increases density, refractive index and hardness of glasses Lanthanum oxide is used in electrode materials and

Lutetium oxide (Lu 2 O 3 ) is the oxide form compound of one of the rare earth metal lutetium. Lutetium oxide has also different names like lutecia and lutetium sesquioxide. Lutetium oxide has a white color. Lutetium oxide is not soluble in water. Lutetium oxide has a cubic crystal structure. 2487 o C is the melting point, which quite high enough, of lutetium oxide compound. Due to lutetium oxide’s air sensitivity lutetium oxide is compatible with strong oxidizing agents. Therefore, there is need for lutetium oxide to be avoided from moisture and carbon dioxide. Moreover, lutetium oxide is the one of the promising laser host materials for high power and ultrashort pulse lasers. Lutetium oxide has a wide band gap (5.5eV). Lutetium oxide is used as cracking, alkylation, hydrogenation and polymerization Lutetium oxide is used as specialty in ceramics, glass, phosphorous and lasers Lutetium oxide is used as starting material in the production of laser crystals Lutetium oxide i

Neodymium oxide (Nd 2 O 3 ) is the one of the rare earth oxides. Neodymium oxide can be also called as neodymium sesquioxide. Neodymium oxide has a light bluish gray color. The hexagonal crystal structure is the only structure that neodymium oxide could appear. Neodymium oxide is almost insoluble in water, 0.00003 gram per 100 ml, but neodymium oxide could be dissolved in acids. Neodymium oxide is thermally stable compound, and neodymium oxide has a hygroscopic nature which may be resulted in formation of neodymium hydroxide. In other words, neodymium oxide is not compatible with strong oxidizing agents. Neodymium oxide has a high dielectric constant. Moreover, neodymium oxide has good insulating properties and an appropriate band offset with Si for microelectronic applications. Neodymium oxide is used in solid-state lasers, carbon arc-light electrodes and enamels Neodymium oxide is used to dope glasses, including sunglasses which are used in welding goggles and other colored