2. Electronic levels in semiconductors 半导体内电子能级分布

The Behavior of Electrons in aSemiconductoris a fascinating topic that has been the subject of much research over the years. Semiconductors are materials that can partially conduct electricity, and their behavior is dependent on the presence or absence of electrons in their crystal structure.One of the key features of a semiconductor is its energy band structure. In a semiconductor, there are two types of energy bands - the valence band and the conduction band. The valence band is where the electrons that are bound to the atoms in the crystal structure exist, while the conduction band is where the electrons that can move freely exist.is affected by a number of different factors. One important factor is the concentration of impurities in the material. Impurities are atoms that have been deliberately added to the semiconductor to change its electrical properties. For example, adding boron to silicon creates a p-type semiconductor, while adding phosphorus creates an n-type semiconductor.In a p-type semiconductor, the concentration of impurities is such that there is a relative shortage of electrons, and the holes left behind by the missing electrons behave as if they were positive charges. This has the effect of attracting electrons to the area, creating a flow of current. In contrast, in an n-type semiconductor, the concentration of impurities is such that there is an excess of electrons, which can move freely through the material.Another important factor that affects the behavior of electrons in a semiconductor is temperature. At low temperatures, the behavior of electrons is dominated by their interaction with the crystal lattice of the material. As the temperature increases, however, electrons can gain enough energy to move into the conduction band, where they can move freely and conduct electricity.In addition to temperature and impurities, the behavior of electrons in a semiconductor is also affected by the presence of electric fields. When an electric field is applied to a semiconductor, it can cause the electrons to move in a particular direction, which can be used to create a current, or to control the behavior of the material.is a complex topic, and there is still much to learn about the interactions between electrons and the crystal lattice of the material. However, the ability to control this behavior has led to the development of many of the technologies that we take for granted today, from computer chips to solar cells.In conclusion, the behavior of electrons in a semiconductor is a fascinating topic that has been the subject of much research over the years. Understanding the interaction between electrons and the crystal lattice of the material is key to our ability to control the behavior of semiconductors and to develop new technologies that rely on their unique properties.。

Semiconductor Manufacturing Technology半导体制造技术Instructor’s ManualMichael QuirkJulian SerdaCopyright Prentice HallTable of Contents目录OverviewI. Chapter1. Semiconductor industry overview2. Semiconductor materials3. Device technologies—IC families4. Silicon and wafer preparation5. Chemicals in the industry6. Contamination control7. Process metrology8. Process gas controls9. IC fabrication overview10. Oxidation11. Deposition12. Metallization13. Photoresist14. Exposure15. Develop16. Etch17. Ion implant18. Polish19. Test20. Assembly and packagingII. Answers to End-of-Chapter Review QuestionsIII. Test Bank (supplied on diskette)IV. Chapter illustrations, tables, bulleted lists and major topics (supplied on CD-ROM)Notes to Instructors:1)The chapter overview provides a concise summary of the main topics in each chapter.2)The correct answer for each test bank question is highlighted in bold. Test bankquestions are based on the end-of-chapter questions. If a student studies the end-of-chapter questions (which are linked to the italicized words in each chapter), then they will be successful on the test bank questions.2Chapter 1Introduction to the Semiconductor Industry Die:管芯 defective:有缺陷的Development of an Industry•The roots of the electronic industry are based on the vacuum tube and early use of silicon for signal transmission prior to World War II. The first electronic computer, the ENIAC, wasdeveloped at the University of Pennsylvania during World War II.•William Shockley, John Bardeen and Walter Brattain invented the solid-state transistor at Bell Telephone Laboratories on December 16, 1947. The semiconductor industry grew rapidly in the 1950s to commercialize the new transistor technology, with many early pioneers working inSilicon Valley in Northern California.Circuit Integration•The first integrated circuit, or IC, was independently co-invented by Jack Kilby at Texas Instruments and Robert Noyce at Fairchild Semiconductor in 1959. An IC integrates multiple electronic components on one substrate of silicon.•Circuit integration eras are: small scale integration (SSI) with 2 - 50 components, medium scale integration (MSI) with 50 – 5k components, large scale integration (LSI) with 5k to 100kcomponents, very large scale integration (VLSI) with 100k to 1M components, and ultra large scale integration (ULSI) with > 1M components.1IC Fabrication•Chips (or die) are fabricated on a thin slice of silicon, known as a wafer (or substrate). Wafers are fabricated in a facility known as a wafer fab, or simply fab.•The five stages of IC fabrication are:Wafer preparation: silicon is purified and prepared into wafers.Wafer fabrication: microchips are fabricated in a wafer fab by either a merchant chip supplier, captive chip producer, fabless company or foundry.Wafer test: Each individual die is probed and electrically tested to sort for good or bad chips.Assembly and packaging: Each individual die is assembled into its electronic package.Final test: Each packaged IC undergoes final electrical test.•Key semiconductor trends are:Increase in chip performance through reduced critical dimensions (CD), more components per chip (Moore’s law, which predicts the doubling of components every 18-24 months) andreduced power consumption.Increase in chip reliability during usage.Reduction in chip price, with an estimated price reduction of 100 million times for the 50 years prior to 1996.The Electronic Era•The 1950s saw the development of many different types of transistor technology, and lead to the development of the silicon age.•The 1960s were an era of process development to begin the integration of ICs, with many new chip-manufacturing companies.•The 1970s were the era of medium-scale integration and saw increased competition in the industry, the development of the microprocessor and the development of equipment technology. •The 1980s introduced automation into the wafer fab and improvements in manufacturing efficiency and product quality.•The 1990s were the ULSI integration era with the volume production of a wide range of ICs with sub-micron geometries.Career paths•There are a wide range of career paths in semiconductor manufacturing, including technician, engineer and management.2Chapter 2 Characteristics of Semiconductor MaterialsAtomic Structure•The atomic model has three types of particles: neutral neutrons（不带电的中子）, positively charged protons（带正电的质子）in the nucleus and negatively charged electrons（带负电的核外电子） that orbit the nucleus. Outermost electrons are in the valence shell, and influence the chemical and physical properties of the atom. Ions form when an atom gains or loses one or more electrons.The Periodic Table•The periodic table lists all known elements. The group number of the periodic table represents the number of valence shell electrons of the element. We are primarily concerned with group numbers IA through VIIIA.•Ionic bonds are formed when valence shell electrons are transferred from the atoms of one element to another. Unstable atoms (e.g., group VIIIA atoms because they lack one electron) easily form ionic bonds.•Covalent bonds have atoms of different elements that share valence shell electrons.3Classifying Materials•There are three difference classes of materials:ConductorsInsulatorsSemiconductors•Conductor materials have low resistance to current flow, such as copper. Insulators have high resistance to current flow. Capacitance is the storage of electrical charge on two conductive plates separated by a dielectric material. The quality of the insulation material between the plates is the dielectric constant. Semiconductor materials can function as either a conductor or insulator.Silicon•Silicon is an elemental semiconductor material because of four valence shell electrons. It occurs in nature as silica and is refined and purified to make wafers.•Pure silicon is intrinsic silicon. The silicon atoms bond together in covalent bonds, which defines many of silicon’s properties. Silicon atoms bond together in set, repeatable patterns, referred to asa crystal.•Germanium was the first semiconductor material used to make chips, but it was soon replaced by silicon. The reasons for this change are:Abundance of siliconHigher melting temperature for wider processing rangeWide temperature range during semiconductor usageNatural growth of silicon dioxide•Silicon dioxide (SiO2) is a high quality, stable electrical insulator material that also serves as a good chemical barrier to protect silicon from external contaminants. The ability to grow stable, thin SiO2 is fundamental to the fabrication of Metal-Oxide-Semiconductor (MOS) devices. •Doping increases silicon conductivity by adding small amounts of other elements. Common dopant elements are from trivalent, p-type Group IIIA (boron) and pentavalent, n-type Group VA (phosphorus, arsenic and antimony).•It is the junction between the n-type and p-type doped regions (referred to as a pn junction) that permit silicon to function as a semiconductor.4Alternative Semiconductor Materials•The alternative semiconductor materials are primarily the compound semiconductors. They are formed from Group IIIA and Group VA (referred to as III-V compounds). An example is gallium arsenide (GaAs).•Some alternative semiconductors come from Group IIA and VIA, referred to as II-VI compounds. •GaAs is the most common III-V compound semiconductor material. GaAs ICs have greater electron mobility, and therefore are faster than ICs made with silicon. GaAs ICs also have higher radiation hardness than silicon, which is better for space and military applications. The primary disadvantage of GaAs is the lack of a natural oxide.5Chapter 3Device TechnologiesCircuit Types•There are two basic types of circuits: analog and digital. Analog circuits have electrical data that varies continuously over a range of voltage, current and power values. Digital circuits have operating signals that vary about two distinct voltage levels – a high and a low.Passive Component Structures•Passive components such as resistors and capacitors conduct electrical current regardless of how the component is connected. IC resistors are a passive component. They can have unwanted resistance known as parasitic resistance. IC capacitor structures can also have unintentional capacitanceActive Component Structures•Active components, such as diodes and transistors can be used to control the direction of current flow. PN junction diodes are formed when there is a region of n-type semiconductor adjacent to a region of p-type semiconductor. A difference in charge at the pn junction creates a depletion region that results in a barrier voltage that must be overcome before a diode can be operated. A bias voltage can be configured to have a reverse bias, with little or no conduction through the diode, or with a forward bias, which permits current flow.•The bipolar junction transistor (BJT) has three electrodes and two pn junctions. A BJT is configured as an npn or pnp transistor and biased for conduction mode. It is a current-amplifying device.6• A schottky diode is formed when metal is brought in contact with a lightly doped n-type semiconductor material. This diode is used in faster and more power efficient BJT circuits.•The field-effect transistor (FET), a voltage-amplifying device, is more compact and power efficient than BJT devices. A thin gate oxide located between the other two electrodes of the transistor insulates the gate on the MOSFET. There are two categories of MOSFETs, nMOS (n-channel) and pMOS (p-channel), each which is defined by its majority current carriers. There is a biasing scheme for operating each type of MOSFET in conduction mode.•For many years, nMOS transistors have been the choice of most IC manufacturers. CMOS, with both nMOS and pMOS transistors in the same IC, has been the most popular device technology since the early 1980s.•BiCMOS technology makes use of the best features of both CMOS and bipolar technology in the same IC device.•Another way to categorize FETs is in terms of enhancement mode and depletion mode. The major different is in the way the channels are doped: enhancement-mode channels are doped opposite in polarity to the source and drain regions, whereas depletion mode channels are doped the same as their respective source and drain regions.Latchup in CMOS Devices•Parasitic transistors can create a latchup condition(???????) in CMOS ICs that causes transistors to unintentionally（无心的） turn on. To control latchup, an epitaxial layer is grown on the wafer surface and an isolation barrier（隔离阻障）is placed between the transistors. An isolation layer can also be buried deep below the transistors.Integrated Circuit Productsz There are a wide range of semiconductor ICs found in electrical and electronic products. This includes the linear IC family, which operates primarily with anal3og circuit applications, and the digital IC family, which includes devices that operate with binary bits of data signals.7Chapter 4Silicon and Wafer Preparation8z Semiconductor-Grade Silicon•The highly refined silicon used for wafer fabrication is termed semiconductor-grade silicon (SGS), and sometimes referred to as electronic-grade silicon. The ultra-high purity of semiconductor-grade silicon is obtained from a multi-step process referred to as the Siemens process.Crystal Structure• A crystal is a solid material with an ordered, 3-dimensional pattern over a long range. This is different from an amorphous material that lacks a repetitive structure.•The unit cell is the most fundamental entity for the long-range order found in crystals. The silicon unit cell is a face-centered cubic diamond structure. Unit cells can be organized in a non-regular arrangement, known as a polycrystal. A monocrystal are neatly arranged unit cells.Crystal Orientation•The orientation of unit cells in a crystal is described by a set of numbers known as Miller indices.The most common crystal planes on a wafer are (100), (110), and (111). Wafers with a (100) crystal plane orientation are most common for MOS devices, whereas (111) is most common for bipolar devices.Monocrystal Silicon Growth•Silicon monocrystal ingots are grown with the Czochralski (CZ) method to achieve the correct crystal orientation and doping. A CZ crystal puller is used to grow the silicon ingots. Chunks of silicon are heated in a crucible in the furnace of the puller, while a perfect silicon crystal seed is used to start the new crystal structure.• A pull process serves to precisely replicate the seed structure. The main parameters during the ingot growth are pull rate and crystal rotation. More homogeneous crystals are achieved with a magnetic field around the silicon melt, known as magnetic CZ.•Dopant material is added to the melt to dope the silicon ingot to the desired electrical resistivity.Impurities are controlled during ingot growth. A float-zone crystal growth method is used toachieve high-purity silicon with lower oxygen content.•Large-diameter ingots are grown today, with a transition underway to produce 300-mm ingot diameters. There are cost benefits for larger diameter wafers, including more die produced on a single wafer.Crystal Defects in Silicon•Crystal defects are interruptions in the repetitive nature of the unit cell. Defect density is the number of defects per square centimeter of wafer surface.•Three general types of crystal defects are: 1) point defects, 2) dislocations, and 3) gross defects.Point defects are vacancies (or voids), interstitial (an atom located in a void) and Frenkel defects, where an atom leaves its lattice site and positions itself in a void. A form of dislocation is astacking fault, which is due to layer stacking errors. Oxygen-induced stacking faults are induced following thermal oxidation. Gross defects are related to the crystal structure (often occurring during crystal growth).Wafer Preparation•The cylindrical, single-crystal ingot undergoes a series of process steps to create wafers, including machining operations, chemical operations, surface polishing and quality checks.•The first wafer preparation steps are the shaping operations: end removal, diameter grinding, and wafer flat or notch. Once these are complete, the ingot undergoes wafer slicing, followed by wafer lapping to remove mechanical damage and an edge contour. Wafer etching is done to chemically remove damage and contamination, followed by polishing. The final steps are cleaning, wafer evaluation and packaging.Quality Measures•Wafer suppliers must produce wafers to stringent quality requirements, including: Physical dimensions: actual dimensions of the wafer (e.g., thickness, etc.).Flatness: linear thickness variation across the wafer.Microroughness: peaks and valleys found on the wafer surface.Oxygen content: excessive oxygen can affect mechanical and electrical properties.Crystal defects: must be minimized for optimum wafer quality.Particles: controlled to minimize yield loss during wafer fabrication.Bulk resistivity(电阻系数): uniform resistivity from doping during crystal growth is critical. Epitaxial Layer•An epitaxial layer (or epi layer) is grown on the wafer surface to achieve the same single crystal structure of the wafer with control over doping type of the epi layer. Epitaxy minimizes latch-up problems as device geometries continue to shrink.Chapter 5Chemicals in Semiconductor FabricationEquipment Service Chase Production BayChemical Supply Room Chemical Distribution Center Holding tank Chemical drumsProcess equipmentControl unit Pump Filter Raised and perforated floorElectronic control cablesSupply air ductDual-wall piping for leak confinement PumpFilterChemical control and leak detection Valve boxes for leak containment Exhaust air ductStates of Matter• Matter in the universe exists in 3 basic states (宇宙万物存在着三种基本形态): solid, liquid andgas. A fourth state is plasma.Properties of Materials• Material properties are the physical and chemical characteristics that describe its unique identity.• Different properties for chemicals in semiconductor manufacturing are: temperature, pressure andvacuum, condensation, vapor pressure, sublimation and deposition, density, surface tension, thermal expansion and stress.Temperature is a measure of how hot or cold a substance is relative to another substance. Pressure is the force exerted per unit area. Vacuum is the removal of gas molecules.Condensation is the process of changing a gas into a liquid. Vaporization is changing a liquidinto a gas.Vapor pressure is the pressure exerted by a vapor in a closed container at equilibrium.Sublimation is the process of changing a solid directly into a gas. Deposition is changing a gas into a solid.Density is the mass of a substance divided by its volume.Surface tension of a liquid is the energy required to increase the surface area of contact.Thermal expansion is the increase in an object’s dimension due to heating.Stress occurs when an object is exposed to a force.Process Chemicals•Semiconductor manufacturing requires extensive chemicals.• A chemical solution is a chemical mixture. The solvent is the component of the solution present in larger amount. The dissolved substances are the solutes.•Acids are solutions that contain hydrogen and dissociate in water to yield hydronium ions. A base is a substance that contains the OH chemical group and dissociates in water to yield the hydroxide ion, OH-.•The pH scale is used to assess the strength of a solution as an acid or base. The pH scale varies from 0 to 14, with 7 being the neutral point. Acids have pH below 7 and bases have pH values above 7.• A solvent is a substance capable of dissolving another substance to form a solution.• A bulk chemical distribution (BCD) system is often used to deliver liquid chemicals to the process tools. Some chemicals are not suitable for BCD and instead use point-of-use (POU) delivery, which means they are stored and used at the process station.•Gases are generally categorized as bulk gases or specialty gases. Bulk gases are the relatively simple gases to manufacture and are traditionally oxygen, nitrogen, hydrogen, helium and argon.The specialty gases, or process gases, are other important gases used in a wafer fab, and usually supplied in low volume.•Specialty gases are usually transported to the fab in metal cylinders.•The local gas distribution system requires a gas purge to flush out undesirable residual gas. Gas delivery systems have special piping and connections systems. A gas stick controls the incoming gas at the process tool.•Specialty gases may be classified as hydrides, fluorinated compounds or acid gases.Chapter 6Contamination Control in Wafer FabsIntroduction•Modern semiconductor manufacturing is performed in a cleanroom, isolated from the outside environment and contaminants.Types of contamination•Cleanroom contamination has five categories: particles, metallic impurities, organic contamination, native oxides and electrostatic discharge. Killer defects are those causes of failure where the chip fails during electrical test.Particles: objects that adhere to a wafer surface and cause yield loss. A particle is a killer defect if it is greater than one-half the minimum device feature size.Metallic impurities: the alkali metals found in common chemicals. Metallic ions are highly mobile and referred to as mobile ionic contaminants (MICs).Organic contamination: contains carbon, such as lubricants and bacteria.Native oxides: thin layer of oxide growth on the wafer surface due to exposure to air.Electrostatic discharge (ESD): uncontrolled transfer of static charge that can damage the microchip.Sources and Control of Contamination•The sources of contamination in a wafer fab are: air, humans, facility, water, process chemicals, process gases and production equipment.Air: class number designates the air quality inside a cleanroom by defining the particle size and density.Humans: a human is a particle generator. Humans wear a cleanroom garment and follow cleanroom protocol to minimize contamination.Facility: the layout is generally done as a ballroom (open space) or bay and chase design.Laminar airflow with air filtering is used to minimize particles. Electrostatic discharge iscontrolled by static-dissipative materials, grounding and air ionization.Ultrapure deiniozed (DI) water: Unacceptable contaminants are removed from DI water through filtration to maintain a resistivity of 18 megohm-cm. The zeta potential represents a charge on fine particles in water, which are trapped by a special filter. UV lamps are used for bacterial sterilization.Process chemicals: filtered to be free of contamination, either by particle filtration, microfiltration (membrane filter), ultrafiltration and reverse osmosis (or hyperfiltration).Process gases: filtered to achieve ultraclean gas.Production equipment: a significant source of particles in a fab.Workstation design: a common layout is bulkhead equipment, where the major equipment is located behind the production bay in the service chase. Wafer handling is done with robotic wafer handlers. A minienvironment is a localized environment where wafers are transferred on a pod and isolated from contamination.Wafer Wet Cleaning•The predominant wafer surface cleaning process is with wet chemistry. The industry standard wet-clean process is the RCA clean, consisting of standard clean 1 (SC-1) and standard clean 2 (SC-2).•SC-1 is a mixture of ammonium hydroxide, hydrogen peroxide and DI water and capable of removing particles and organic materials. For particles, removal is primarily through oxidation of the particle or electric repulsion.•SC-2 is a mixture of hydrochloric acid, hydrogen peroxide and DI water and used to remove metals from the wafer surface.•RCA clean has been modified with diluted cleaning chemistries. The piranha cleaning mixture combines sulfuric acid and hydrogen peroxide to remove organic and metallic impurities. Many cleaning steps include an HF last step to remove native oxide.•Megasonics(兆声清洗) is widely used for wet cleaning. It has ultrasonic energy with frequencies near 1 MHz. Spray cleaning will spray wet-cleaning chemicals onto the wafer. Scrubbing is an effective method for removing particles from the wafer surface.•Wafer rinse is done with overflow rinse, dump rinse and spray rinse. Wafer drying is done with spin dryer or IPA(异丙醇) vapor dry (isopropyl alcohol).•Some alternatives to RCA clean are dry cleaning, such as with plasma-based cleaning, ozone and cryogenic aerosol cleaning.Chapter 7Metrology and Defect InspectionIC Metrology•In a wafer fab, metrology refers to the techniques and procedures for determining physical and electrical properties of the wafer.•In-process data has traditionally been collected on monitor wafers. Measurement equipment is either stand-alone or integrated.•Yield is the percent of good parts produced out of the total group of parts started. It is an indicator of the health of the fabrication process.Quality Measures•Semiconductor quality measures define the requirements for specific aspects of wafer fabrication to ensure acceptable device performance.•Film thickness is generally divided into the measurement of opaque film or transparent film. Sheet resistance measured with a four-point probe is a common method of measuring opaque films (e.g., metal film). A contour map shows sheet resistance deviations across the wafer surface.•Ellipsometry is a nondestructive, noncontact measurement technique for transparent films. It works based on linearly polarized light that reflects off the sample and is elliptically polarized.•Reflectometry is used to measure a film thickness based on how light reflects off the top and bottom surface of the film layer. X-ray and photoacoustic technology are also used to measure film thickness.•Film stress is measured by analyzing changes in the radius of curvature of the wafer. Variations in the refractive index are used to highlight contamination in the film.•Dopant concentration is traditionally measured with a four-point probe. The latest technology is the thermal-wave system, which measures the lattice damage in the implanted wafer after ion implantation. Another method for measuring dopant concentration is spreading resistance probe. •Brightfield detection is the traditional light source for microscope equipment. An optical microscope uses light reflection to detect surface defects. Darkfield detection examines light scattered off defects on the wafer surface. Light scattering uses darkfield detection to detectsurface particles by illuminating the surface with laser light and then using optical imaging.•Critical dimensions (CDs) are measured to achieve precise control over feature size dimensions.The scanning electron microscope is often used to measure CDs.•Conformal step coverage is measured with a surface profiler that has a stylus tip.•Overlay registration measures the ability to accurately print photoresist patterns over a previously etched pattern.•Capacitance-voltage (C-V) test is used to verify acceptable charge conditions and cleanliness at the gate structure in a MOS device.Analytical Equipment•The secondary-ion mass spectrometry (SIMS) is a method of eroding a wafer surface with accelerated ions in a magnetic field to analyze the surface material composition.•The atomic force microscope (AFM) is a surface profiler that scans a small, counterbalanced tip probe over the wafer to create a 3-D surface map.•Auger electron spectroscopy (AES) measures composition on the wafer surface by measuring the energy of the auger electrons. It identifies elements to a depth of about 2 nm. Another instrument used to identify surface chemical species is X-ray photoelectron spectroscopy (XPS).•Transmission electron microscopy (TEM) uses a beam of electrons that is transmitted through a thin slice of the wafer. It is capable of quantifying very small features on a wafer, such as silicon crystal point defects.•Energy-dispersive spectrometer (EDX) is a widely used X-ray detection method for identifying elements. It is often used in conjunction with the SEM.• A focused ion beam (FIB) system is a destructive technique that focuses a beam of ions on the wafer to carve a thin cross section from any wafer area. This permits analysis of the wafermaterial.Chapter 8Gas Control in Process ChambersEtch process chambers••The process chamber is a controlled vacuum environment where intended chemical reactions take place under controlled conditions. Process chambers are often configured as a cluster tool. Vacuum•Vacuum ranges are low (rough) vacuum, medium vacuum, high vacuum and ultrahigh vacuum (UHV). When pressure is lowered in a vacuum, the mean free path(平均自由行程) increases, which is important for how gases flow through the system and for creating a plasma.Vacuum Pumps•Roughing pumps are used to achieve a low to medium vacuum and to exhaust a high vacuum pump. High vacuum pumps achieve a high to ultrahigh vacuum.•Roughing pumps are dry mechanical pumps or a blower pump (also referred to as a booster). Two common high vacuum pumps are a turbomolecular (turbo) pump and cryopump. The turbo pump is a reliable, clean pump that works on the principle of mechanical compression. The cryopump isa capture pump that removes gases from the process chamber by freezing them.。

半导体分离芯材料英语Semiconductor Materials for Isolation Cores.Semiconductor materials play a crucial role in modern electronics, particularly in the fabrication of isolation cores. Isolation cores are essential components in integrated circuits, ensuring that different sections of the circuit operate independently without interference. This article delves into the world of semiconductor materials suitable for isolation cores, discussing their properties, applications, and challenges.1. Introduction to Semiconductor Materials.Semiconductors are materials that have an electrical conductivity falling between that of conductors and insulators. They exhibit unique electronic properties, making them ideal for use in electronic devices. Silicon (Si) and germanium (Ge) are the most commonly used semiconductors, but others such as gallium arsenide (GaAs)and silicon carbide (SiC) are also finding applications in specific areas.2. Properties of Semiconductor Materials.Bandgap Energy: The bandgap energy is a measure of the energy required to excite an electron from the valence band to the conduction band. Materials with larger bandgap energies are better suited for high-temperature applications.Doping: Semiconductors can be doped with impurities to alter their conductivity. Dopants such as boron (B) or phosphorus (P) are introduced to create p-type or n-type semiconductors, respectively.Lattice Structure: The atomic lattice structure of semiconductors determines their physical and electrical properties. Silicon and germanium have diamond-like lattice structures, which contribute to their widespread use.3. Isolation Cores and Their Importance.Isolation cores are critical in integrated circuits, where they prevent electrical signals from leaking between different circuit sections. This isolation ensures that signals are contained within their designated paths, preventing crosstalk and noise. Isolation cores are typically made from insulating materials, but semiconductor materials can also be used to achieve isolation.4. Semiconductor Materials for Isolation Cores.Silicon-on-Insulator (SOI): SOI technology involves a thin layer of silicon sandwiched between two layers of insulating material, such as silicon dioxide or sapphire. This structure provides excellent isolation between different circuit sections. SOI wafers are widely used in high-performance microelectronics, as they offer reduced parasitic capacitance and improved thermal performance.Silicon Carbide (SiC): SiC is a wide-bandgap semiconductor material with excellent thermal conductivity and chemical stability. It is suitable for high-temperatureand high-power applications. SiC-based isolation cores can withstand extreme operating conditions, making them idealfor use in power electronics and aerospace applications.Gallium Arsenide (GaAs): GaAs has a smaller bandgap than silicon but offers higher electron mobility and saturation velocity. GaAs-based isolation cores are commonly used in high-frequency applications such as microwave and millimeter-wave circuits. GaAs also finds applications in optoelectronics due to its ability to emit and detect light.5. Challenges and Future Outlook.Despite the many advantages of semiconductor materials for isolation cores, there are still challenges to overcome. One major challenge is the scalability of these materialsfor smaller and more complex integrated circuits. Another challenge lies in the fabrication process, which requires precise control over doping levels, lattice structures, and defect densities.Future research in this area will focus on developing new semiconductor materials with improved properties and on optimizing fabrication processes for better scalability and performance. Materials such as two-dimensional semiconductors and topological insulators are beingactively explored for their potential in next-generation electronics.Conclusion.Semiconductor materials play a pivotal role in the fabrication of isolation cores, enabling the reliable operation of integrated circuits. Silicon, silicon carbide, and gallium arsenide are among the most commonly used semiconductors for this purpose, each offering its unique advantages and applications. Future research in this field will focus on addressing challenges related to scalability and fabrication processes while exploring novel materials with improved properties.。

半导体器件英文版Semiconductor devices are electronic components thatutilize the unique properties of semiconductors to perform various functions in electronic circuits. These devices playa crucial role in modern technology and are essential for the operation of almost all electronic devices.One of the most common types of semiconductor devices is the diode, which allows current to flow in only one direction. Diodes are used in rectifiers to convert alternating current (AC) to direct current (DC) and in circuits to protect components from reverse voltage.Transistors are another important semiconductor devicethat are used to amplify or switch electronic signals. There are two main types of transistors: bipolar junctiontransistors (BJTs) and field-effect transistors (FETs). BJTsuse a current to control the flow of another current, while FETs use an electric field to control the flow of current.Integrated circuits (ICs) are semiconductor devices that contain thousands or even millions of individual components, such as transistors, diodes, and resistors, all embedded on a single semiconductor chip. ICs are the building blocks of most electronic devices and can be found in smartphones, computers, televisions, and many other electronic gadgets.Another important semiconductor device is the light-emitting diode (LED), which emits light when an electric current passes through it. LEDs are widely used in displays, indicators, and lighting applications due to their energy efficiency and long lifespan.Semiconductor devices have revolutionized the electronics industry and have enabled the development of advanced technologies such as computers, smartphones, and renewable energy systems. As semiconductor technology continues toevolve, new devices with improved performance and capabilities are being developed to meet the increasing demands of modern electronics.。

半导体的原理与应用英语1. Introduction to SemiconductorsSemiconductors are materials that have electrical conductivity between conductors (such as metals) and insulators (such as ceramics). They have unique electronic properties that make them essential in various electronic devices. This article aims to provide an overview of the principles and applications of semiconductors in English.2. Basic Principles of SemiconductorsSemiconductors rely on the behavior of electrons and holes within their crystalline structure. The key principle is the band gap, which is the energy difference between the valence band (electron-rich) and the conduction band (electron-poor). At absolute zero temperature, semiconductors have a fully occupied valence band and an empty conduction band. However, at higher temperatures or with external energy input, electrons can be excited to the conduction band, creating a conductive pathway.3. Types of SemiconductorsThere are two main types of semiconductors: intrinsic and extrinsic. Intrinsic semiconductors are pure semiconducting materials, such as silicon (Si) and germanium (Ge). Extrinsic semiconductors are doped with impurities to alter their electrical properties. Two common types of extrinsic semiconductors include n-type (electron-doped) and p-type (hole-doped) semiconductors.4. Doping Process in SemiconductorsDoping introduces impurities into the semiconductor crystal, which modifies its electrical conductivity. For n-type doping, atoms with more valence electrons, such as phosphorus (P), are added. These extra electrons become the majority charge carriers, increasing conductivity. In contrast, p-type doping involves adding atoms with fewer valence electrons, such as boron (B). These。

半导体英文词汇SemiconductorA semiconductor is a material that has electrical conductivity between that of a conductor and that of an insulator. This means that it can conduct some electricity under certain conditions, but not as much as a conductor. Semiconductors are essential components of electronic devices, such as diodes, transistors, and integrated circuits.半导体半导体是一种在导体和绝缘体之间具有电导性的材料。

这意味着在某些条件下它可以导电，但不像导体那样能够导电。

半导体是电子器件的基本组成部分，如二极管、晶体管和集成电路。

DiodeA diode is a semiconductor device that allows current to flow in only one direction. It has two terminals, an anode and a cathode. When a positive voltage is applied to the anode and a negative voltage to the cathode, the diode conducts electricity. However, if the polarity of theapplied voltage is reversed, the diode blocks the flow of current.二极管二极管是一种只允许电流在一个方向中流动的半导体器件。

电子信息技术专业英语习题答案电子信息技术专业英语第2版习题答案Exercise AnswersPart one ElectronicsUnit 1 Electronic ComponentsExercises1.(1)the simplest components in any circuit(2)converting electrical energy into heat.(3)仅沿单向流动(4)on or off switch(5)称为电绝缘的绝缘材料2. (1)current(2)circuit(3)charge(4)conductors(5)Transistors3. (1)which ---atoms(2)it---balloon(3)it---The unit of voltage, or potential difference(4)which---a wall or the ceiling(5)it---the charge of an electron is a negative one of 1.60218x10-19 coulombs4. (1)constitute(2)consists of(3)is composed of(4)makes up(5)constitute5. (1) Resistors can reduce the flow of current.(2) Capacitors consist of two pieces of conducting materials separated by a non-conducting material called a dielectric.(3)The function of a transistor is similar to a switch.Unit 2 SemiconductorExercises1．(1)集成电路(2)半导体的导电性(3)positive type material semiconductor(4)forward bias(5)每秒可完成上百万的简单指令操作2．(1)---(a)(2)---(c)(3)---(b)(4)---(e)(5)---(d)3. (1)√(2)x (3)x (4)√ (5) √4.(1)只要加很小的电压就能让电流流动的材料称为导体。

第一单元 元件与定律A ．课文译文电阻器、电容器和电感器在电子电路中，电阻器、电容器和电感器是非常重要的元件。

电阻器和电阻电阻器是二端口元件。

电阻是阻止电流流动，更确切地说，是阻止电荷流动的能力。

在国际单位制中，电阻用欧姆来度量。

希腊字母Ω是欧姆的标准符号。

较大的电阻一般用千欧和兆欧来表示。

模拟这种特性常用的电路元件是电阻器。

图1.1表示电阻器的电路符号，R 表示电阻器的电阻值。

图1.1 电阻器的电路符号为了进行电路分析，我们必须在电阻器中指明电流和电压的参考方向。

如果我们选择关联参考方向，那么电压和电流之间的关系是：v =iR (1.1)这里 v 是电压，其单位是伏特， i 是电流，其单位是安培， R 是电阻，其单位是欧姆。

如果选择非关联参考方向，我们必须写成：v =－iR (1.2)用在公式（1.1）和（1.2）中的代数式就是著名的欧姆定律。

欧姆定律表示了电压作为电流的函数。

然而，要表示电流是电压的函数也是非常方便的。

欧姆定律是电阻两端的电压和电流间的代数关系。

电容器和电容电能可以存储在电场中，存储电能的装置叫电容器。

电容器存储电能的能力叫做电容。

图1.2表示电容器的电路符号。

电容的电路参数用字母C 表示，用法拉来度量。

因为法拉是相当大的电容量，实际上电容值通常位于皮法和微法之间。

图1.2 电容器的电路符号当电压随时间变化时，电荷的位移也随时间变化，引起了众所周知的位移电流。

在终端，位移电流和传导电流没有区别。

当电流参考方向和电压参考方向是关联参考方向时，电流正比于电容两端电压随时间的变化率的数学表达式为：dtdv C i = (1.3) 这里 i 的单位是安培，C 的单位是法拉，v 的单位是伏特， t 的单位是秒。

电感器和电感众所周知，电感是电子电路中的模块之一。

所有的线圈都有电感。

电感是抵抗流过线圈电流的任何变化的性质。

电感用字母L 表示，其单位是亨利。

图1.3表示一个电感器。

图1.3 电感器的电路符号当电流和电压的参考方向关联时，有dt diL v = (1.4)这里v 的单位是伏特，L 的单位是亨利，i 的单位是安培，t 的单位是秒。

——电材专业英语课文翻译Semiconductor Materials• 1.1 Energy Bands and Carrier Concentration• 1.1.1 Semiconductor Materials•Solid-state materials can be grouped into three classes—insulators(绝缘体）, semiconductors, and conductors. Figure 1-1 shows the electrical conductivities δ(and the corresponding resistivities ρ≡1/δ)associated with(相关）some important materials in each of three classes. Insulators such as fused（熔融）quartz and glass have very low conductivities, in the order of 1E-18 to 1E-8 S/cm;固态材料可分为三种：绝缘体、半导体和导体。

图1－1 给出了在三种材料中一些重要材料相关的电阻值（相应电导率ρ≡1/δ)。

绝缘体如熔融石英和玻璃具有很低电导率，在10-18 到10-8 S/cm;and conductors such as aluminum and silver have high conductivities, typically from 104 to 106 S/cm. Semiconductors have conductivities between those of insulators and those of conductors. The conductivity of a semiconductor is generally sensitive to temperature, illumination（照射）, magnetic field, and minute amount of impurity atoms. This sensitivity in conductivity makes the semiconductor one of the most important materials for electronic applications.导体如铝和银有高的电导率，典型值从104到106S/cm;而半导体具有的电导率介乎于两者之间。

第2单元电子基础第3课半导体材料通常，根据材料导电性能的不同，可分为三种类型——导体，半导体和绝缘体。

半导体是一种导电能力介于导体和绝缘体之间的材料，其导电性在外部电场的作用下是变化的。

半导体材料的导电性能比导体差，但是相对于绝缘体来说其导电性能比较好。

早在19世纪就开始对半导体材料进行研究，多年以来，许多半导体材料已经开发。

表1-1为半导体化学元素周期表的一部分。

元素半导体是由单一元素制成的半导体材料。

例如IV族元素硅、锗和锡和VI族元素硒和锑。

大多数化合物半导体材料由两种或两种以上元素组成。

如砷化镓是III-V族化合物。

它是由III族的镓元素和V族的砷元素组成。

由半导体材料制成的电子器件非常微小。

利用半导体材料的性质可以制造出功能多样的半导体器件。

另外，半导体器件和其他电子器件相比有很多优点，它们体积小、重量轻而且功耗小。

与其他电子器件一样，半导体器件有控制电子移动的能力。

可用作整流器、探测器、放大器、振荡器、电子开关、混频器和调制器等。

通常用于半导体器件的半导体材料是锗和硅，它们是应用最广的半导体材料。

锗和硅都属于金刚石晶格结构，这种结构同时也属于立方晶体族结构。

地球上超过90%的成分由二氧化硅和硅酸盐组成。

硅元素储量丰富，占地球上第二位。

在沙滩上闪闪发亮的就是硅石。

在自然界和工业的许多化合物中均发现有硅成份组成。

对工业技术来讲，最重要的就是硅是半导体器件的基础平台。

大多数的半导体器件都是由硅材料制造的，尤其是集成电路和微芯片。

在集成电路制造中，硅材料是形成单晶硅片的基础。

为了跟上集成电路制造工艺、芯片尺寸和电路复杂程度的步伐，硅晶体和晶圆也必须在增加直径的同时改善其性能。

现在普遍制造的硅片直径已经足够大，可以达到300mm也就是12inch。

图3-1中显示的是一片硅晶圆。

现代的特大规模集成电路，其设计工艺已经要求达到60纳米，这都是由于硅单晶具有非常良好的性质，而且这些硅片都是应用坩埚直拉法形成的。