What is Semiconductor: Definition and 397 Discussions

A semiconductor material has an electrical conductivity value falling between that of a conductor, such as metallic copper, and an insulator, such as glass. Its resistivity falls as its temperature rises; metals behave in the opposite way. Its conducting properties may be altered in useful ways by introducing impurities ("doping") into the crystal structure. When two differently-doped regions exist in the same crystal, a semiconductor junction is created. The behavior of charge carriers, which include electrons, ions and electron holes, at these junctions is the basis of diodes, transistors and most modern electronics. Some examples of semiconductors are silicon, germanium, gallium arsenide, and elements near the so-called "metalloid staircase" on the periodic table. After silicon, gallium arsenide is the second most common semiconductor and is used in laser diodes, solar cells, microwave-frequency integrated circuits, and others. Silicon is a critical element for fabricating most electronic circuits.
Semiconductor devices can display a range of useful properties, such as passing current more easily in one direction than the other, showing variable resistance, and sensitivity to light or heat. Because the electrical properties of a semiconductor material can be modified by doping, or by the application of electrical fields or light, devices made from semiconductors can be used for amplification, switching, and energy conversion.
The conductivity of silicon is increased by adding a small amount (of the order of 1 in 108) of pentavalent (antimony, phosphorus, or arsenic) or trivalent (boron, gallium, indium) atoms. This process is known as doping and the resulting semiconductors are known as doped or extrinsic semiconductors. Apart from doping, the conductivity of a semiconductor can be improved by increasing its temperature. This is contrary to the behavior of a metal in which conductivity decreases with an increase in temperature.
The modern understanding of the properties of a semiconductor relies on quantum physics to explain the movement of charge carriers in a crystal lattice. Doping greatly increases the number of charge carriers within the crystal. When a doped semiconductor contains free holes it is called "p-type", and when it contains free electrons it is known as "n-type". The semiconductor materials used in electronic devices are doped under precise conditions to control the concentration and regions of p- and n-type dopants. A single semiconductor device crystal can have many p- and n-type regions; the p–n junctions between these regions are responsible for the useful electronic behavior. Using a hot-point probe, one can determine quickly whether a semiconductor sample is p- or n-type.Some of the properties of semiconductor materials were observed throughout the mid 19th and first decades of the 20th century. The first practical application of semiconductors in electronics was the 1904 development of the cat's-whisker detector, a primitive semiconductor diode used in early radio receivers. Developments in quantum physics led in turn to the invention of the transistor in 1947, the integrated circuit in 1958, and the MOSFET (metal–oxide–semiconductor field-effect transistor) in 1959.

View More On Wikipedia.org
  1. S

    I Hall effect in P-type semiconductors: electron-centric heuristic?

    The Wikipedia page on the Hall effect says: I probably don't have the math ability or the time to master solid state physics in all its glory, but I am hoping to get to a heuristic picture of the P-type Hall effect that, at the very least, won't be "not even wrong". My attempt is as follows...
  2. Z

    A Bipolar transport in a simple illuminated semiconductor bar

    I feel quite confused for a few days, when I apply the bipolar transport equation into a voltage-applied semicondutor material (e.g. p-type c-Si bar, or a resistor) which just have some light-generated electron-hole pairs by a pulse of photon at somewhere on the bar. In terms of bipolar...
  3. M

    Silvaco: "simulator has unexpectedly exited with status -1073741819"

    Hello, I am simulating the process of NMOS construction. as you know, in order to make the LDD, we need two implantations, one before creating oxide spacer and another after creating oxide spacer. at the last implantation, I am facing an error which is shown in the following image: I put...
  4. V

    What's the chemistry behind a semiconductor?

    This is a confusing subject for me. It's like only getting half of the story. Reading physics but not understanding how it works in chemistry makes it nonsense to me. Imagine we are creating a silicon-based semiconductor. They have covalent bonds between them, with each silicon atom having four...
  5. N

    A Experimental Semiconductor Bandgap Databases

    I'm looking for experimental bandgap information to compare it to DFT calculations from Materials Project and OQMD. Could anyone recommend some?
  6. S

    Semiconductor technology progress for car controllers (ABS, ESP, ....)?

    Hi! How does progress in semiconductor transistors such as Si to SiC or GaN, MOSFET to FinFET, 10nm to 2nm, etc. improves the performance of a controller such as the ABS, ESP, ESC, ... of a car? And how much is the impact of transistor technology progress on such a controller (compared to...
  7. cemtu

    Solid State Good Condensed Matter Physics Books and Semiconductor Physics Books

    Can you please recommend me some condensed matter physics study books and semi-conductor physics study books? Much Appreciated!
  8. LUFER

    What is the Electromagnetic Cross Section in this plasma deposition process?

    What is Electromagnetic Cross Section? (shock section) Hello, I have a question regarding the manufacturing process of electronic components in the case of the silicon deposition and corrosion process. My biggest doubt is the behavior of the plasma interacting in the reactor, I don't know if...
  9. Mayan Fung

    I Measuring the built-in potential of a pn junction

    I am thinking about the reason why we cannot probe the built-in potential across a diode with a voltmeter. Obviously, a diode is not an energy source, so it is impossible for it to show a voltage reading. After doing some research, I found some explanations and some questions about them. 1. The...
  10. ubergewehr273

    I Capping layer in semiconductor quantum dot fabrication

    Hi everyone, I've been studying about semiconductor heterostructures and in particular quantum dots. I was wondering, why is there a need to have a "capping" layer above the layer where the quantum dots are formed within a sample? Thanks in advance!
  11. mcas

    Calculate Conductivity Temperature Dependence in Semiconductors

    I have to plot the conductivity dependence of temperature and I have problems with obtaining the right dependency of \mu and n. But let's focus only on carrier concentration first. For n I used the third equation. From what I understand N_D is a constant. I want my plot to look like this: But...
  12. S

    A What is the Structure of Gallium Oxide?

    I have three questions regarding the material Gallium Oxide. I was reading in several articles and they introduced its structure as it has monoclinic structure and it consists tetrahedral and octahedral structures in it. What I can't understand I can connect this structure to the chemical...
  13. A

    Silicon and Germanium semiconductor mixtures used in component manufacturing?

    Can Silicon and Germanium semiconductors mixture (chemical reaction) with some other chemical elements (if required) assist in creating new and existing robust electronic components? Si + Ge + ? + ? = Can this assist in quantum computing?
  14. Kun-Kun

    Engineering What kind of engineers work in the semiconductor industry?

    What does a MechE/EE/ChemE usually do in this industry? I think that CS/CE works in the software department and architecture. For circuit and stuff, EEs will be working on that. ChemE works on the actual manufacturing of chips. Materials E work in this department too, I think. Am I correct...
  15. P

    Anisotropic Etching in Semiconductor Fabrication

    I am learning about designing semiconductors but I had some issues understanding some things about the structure of Si. About lattice structure: 1) Why does an FCC has 8 atoms per cell? Doesnt has 14? About wafers 1) I know you can have wafers along different surfaces. What information can I...
  16. P

    Semiconductor -- Conduction and Valence bands

    I am a new to this and I try to understand the basics. So initially once the atoms of silicon come together to form a solid, due to Pauli law no electrons can exist in the same energy state,thus many energy states are formed which together make the bands. My problem starts at this stage where I...
  17. N

    Physics Physics Degrees and Semiconductor Industry (IC Design?)

    Hello there, im a physics student from Germany and currently in my second semester of a Bachelor of science. Lately i have become increasingly interested in woking in the Semiconductor Industry and I am currently reading the book "But how do it Know" by J. Clark Scott and i think it is really...
  18. M

    The effect of temperature on phosphorescence

    I had read somewhere that as the temperature increases, its lifetime decreases. But there was no further explanation. Of course, I don't know if it's true yet.
  19. M

    Potential solution:Uses of Transparent Semiconductors: FTO and ITO explained

    Summary:: What is the advantage of transparent semiconductors such as Fluorine doped tin oxide over main semiconductors? What is the advantage of transparent semiconductors such as Fluorine doped tin oxide (FTO) and Indium tin oxide (ITO) over main semiconductors? Please explain the uses of...
  20. Kaushik

    B How does the doping concentration affect the depletion width?

    I do not understand why that is the case. Is there any intuitive explanation for it? Thanks
  21. H

    I Graphene - Armchair vs Zigzag - Semiconductor?

    I have a question concerning the differentiation between the zigzag and armchair pattern of graphene. Specifically concerning the fact that zigzag edges produce metallic properties and armchair edges producing semiconducting/metallic properties. How does this relate to the orientation of...
  22. D

    Semiconductor (Diode) Lasers and Properties

    print ('Calculate threshold, power, slope efficiency for different lengths of SC Laser') g = 510 # The gain of the laser, arbitrary value of 510 m^-1 was picked I = np.linspace(0, 0.03,5) #DRIVE CURRENT; 100 values of current, 'I', between 0A and 0.03AV = 1.8 #INPUT VOLTAGE; arbitrary value of...
  23. Mayan Fung

    I Recombination and open-circuit voltage in solar cells

    From the ideal diode model, we can derive the open-circuit voltage (Voc) as: $$ V_{oc} = \frac{nkT}{q} ln(\frac{I_L}{I_0} + 1) $$ where ##I_0## is the dark saturation current and ##I_L## is the light generated current. From the model, if the recombination rate increases, the dark saturation...
  24. B

    I Fermi level in a nonuniformly doped semiconductor

    Fermi level is known to be constant in a equilibrium state. It is also known to vary according to the number of donors/acceptors. In a nonuniformly doped semiconductor that has varying number of donors/acceptors at different position, how is the fermi level decided? Is it the average number of...
  25. M

    Engineering Contact pontential for a semiconductor

    Anyone can help me, which formula I should use for this question?
  26. M

    Engineering How Does Electron Mobility Relate to Conductivity in N-Type Silicon?

    I still not understand about this, i found so many formulas but I don't know which one i should use for this question
  27. quixote

    Courses Course on Semiconductor Physics as part of my EE degree

    Hey, need a bit of a help. me, an electrical engg. student is confused at this point that my university offers a course(half semester) on "Electronic Devices(ED)" as they call it; as you can infer from the attachment. As I watch the lectures it turns out to be an intermediate course on the...
  28. halleff

    Diffusion current and carrier concentration equilibrium (unbiased)

    Suppose you have a non-uniformly doped piece of semiconductor (without an applied bias) such that the acceptor dopant concentration Na(x) decreases from left to right (as x increases). In this case, the equilibrium hole distribution p(x) will not be uniform since then there would be a net drift...
  29. Athenian

    I Energy of Conduction and Valence Band in Opposing Directions

    Recently, I have been studying some solid-state physics and I came across this ##E-k## diagram online. Here's an image for reference to what I am referring to...
  30. Dor

    !Measuring Currents in a Circuit w/ Semiconductor

    If so, what will I measure in the Ampermeter, the zero total current or the value of the conduction current? I was thinking of the following example- a circuit consist of a current source, an Ampermeter, a switch, and a semiconductor. The semiconductor can have both conduction and displacement...
  31. bob0909090909

    N-type semiconductor -- calculate the doping level

    Completely lost on this question. Any help would be great, even a direction to start moving would be helpful.
  32. S

    Engineering Light absorption in a semiconductor

    The doped a-Si: H layers in a HIT solar cell do not contribute to the photocurrent. The light they absorb (according to their absorption curve below) is lost. For a doped a-Si: H layer at the front side of the cell that is 25nm thick, what percentage of light at 400nm will be lost due to...
  33. F

    Textbook to Precede Physics of Semiconductor Devices (Sze)

    I was recommended to read Physics of Semiconductor Devices by Sze which I was told was the standard textbook for the subject. My background is Electronic Engineering and not physics. After reading the first few pages of the first chapter I am completely overwelmed. I can't make sense of the...
  34. A

    How Does Paracrystallinity Influence Charge Transport in Conjugated Polymers?

    "In the case of negligible paracrystallinity, the density of states (DOS) of the 1D pi-stack depends on the amount of on-site disorder generating a Gaussian tail of states extending into the bandgap (Fig. 3a). Typical pi-stacks of conjugated polymers exhibit moderate amounts of paracrystalline...
  35. jisbon

    Engineering Semiconductor Photoluminescene

    Just wanted to check my understanding as well as my attempted answers here: Since light emission at the wavelength of 326.3 nm due to band-to-band recombination is detected, this means that the electron falls down to the valence band to recombine with a hole (to occupy an empty state close to...
  36. Spinnor

    I Bohm guiding field, electrons in a semiconductor "box"

    Consider the light sensor in a modern camera. Light can give energy to electrons and populate the numerous "boxes" of our light sensor with extra electrons. Those boxes will temporally store the electrons till they are counted. I would like to understand this process with my "Bohmian" glasses...
  37. R

    I Metal Semiconductor contact (Part 2)

    MOS (p type) 1) Figure a) and b) are the cases of strong inversion. Figure b)-For high frequency signals, electrons at the semiconductor oxide interface do not get enough time to change ( I follow that ), but how come the charge in the bulk close to the depletion region changes with these high...
  38. M

    Semiconductor Physics: Definition & Relation to Material Sci

    how you can define the term "Semiconductor Physics" and what is the relation between semiconductor Physics and Material Science?
  39. R

    A Understanding the Charge Distribution at the Metal-Semiconductor Interface

    Assume n type semiconductor: 1) Can the fermi level of metal change when it makes contact with the n type Semiconductor ? What assumptions do we make in ideal situation ? 2) Is the Schottky Barrier in Metal Semiconductor contact remains constant with an applied forward or reverse voltage ? 3) On...
  40. T

    A Shouldn't the shape of a semiconductor laser be planar instead of conical?

    I read about semiconductor laser and its beam shape is conical with 50' of dispersion angle. But for me, it is hard to accept that it is conical because every single drawing I see is rectangular and the plan that laser going out is also a plain, not a hole. And this is the picture I saw...
  41. M

    I What subfields does semiconductor physics comprise?

    What subfields semiconductor physics comprise?
  42. A

    Quantum Theory Of Semiconductor Quantum Dots + other books on this topic

    Hello, I have two questions into one. First I would like to know what books are considered the best to introduce the theory of quantum dots, so for example with the k.p method, tight-binding, empirical pseudopotentials, and other techniques, analytical derivations, optical properties, band...
  43. Muhammad Usman

    I Concentration of Impurities in Extrinsic Semiconductor ?

    Hi, I was studying a book on analysis and design of analog integrated circuits. In the book it is mentioned as "For practical concentration of impurities, the density of majority carriers is approximately equal to the density of impurity atoms in the crystal" I researched about it and I found...
  44. F

    Can't find the effective mass of a 2-dimensional semiconductor

    This is the situation: you have the band structure of a two-dimensional semiconductor E=E(k). Both, valence band and condcution band. You use the definition of effective mass: (m)^(-1)=(d2E/dkidkj), but both bands are in such a way that the 2x2 matrix that you obtain has zero determinant. So...
  45. C

    Semiconductor physics: Voltage below forward voltage

    Assume we have a diode closed circuit.We connect the p type region of the diode to the positive terminal of the battery(cathode).We connect the n type region of the diode to the negative terminal of the battery(anode).The voltage of the battery is 0.3V .The diode%s intristic se miconductor is...
  46. C

    Diode operation from reverse bias to zero bias

    Assume we have a closed diode circuit .We connect the n type region of the diode to the positive terminal of the battery.We connect the p type region of the diode to the negative terminal of the battery.The depletion layer is increased.Now we open the circuit.Why the diode returns to its zero...
  47. archaic

    Load resistance in voltage regulator

    Homework Statement [/B] I want to find the minimum resistance ##R_L## so as to maintain ##V_z##(voltage of the zener corresponding to the minimum current ##I_{z_0}##) across the same resistor ##R_L##. Homework Equations ##V_z##(voltage of the zener corresponding to the minimum current...
  48. Jalo

    I Photodiode bandwidth: why does power decrease with frequency

    Hi, I'm studying p-i-n photodiode (PD) at the moment and understand that the photodiode's response will depend on the frequency of the light signal going into it. I am struggling however to understand the concept of bandwidth, and why is it that the photocurrent at the PD decreases with higher...
  49. P

    A Acceptable Atmosphere for CZ/Float-zone Refining

    Both the cz (Czochralski Process), and Float-zone refining of silicon require an inert atmosphere, usually argon. How pure does the argon atmosphere have to be? How high of a vacuum has to be pulled before releasing argon into the tank?