Semiconductor Definition and 347 Threads

  1. R

    What Is Planar Technology in Semiconductor Sensors?

    what is planar technology?
  2. H

    Why Does N-Type Doping Result in Higher Hole than Electron Concentration?

    Homework Statement Suppose an unknown semiconductor material has bandgap energy of .1 eV. Density of states for conduction and valence bands are both = 10^18cm^-3. If the material is doped with shallow donors (n-type) Nd=10^17cm^-3, what is electron and hole concentrations? Homework...
  3. W

    Effective mass of Si in semiconductor physics

    Hello, I have the problem, from Sze' book, tunneling current, what is m*? I want to konw the value of it. The m* has many reference, how do I select? My interested device is diode that was doped with Boron and Phosphorus for p-n junction. Thank very much.
  4. J

    Quick question about semiconductor alloys and band gaps?

    This seems like a straightforward thing but no textbook I've seen addresses it. Take the direct gap semiconductors GaAs (band gap 1.42 eV) and InAs (band gap 0.42 eV). If these two were alloyed together, would the band gap become some sort of average between the two values? As an example, say...
  5. M

    Semiconductor Electron Affinity

    Hi There, Im doing a study of MOS capacitors (Semiconductor is 4H-SiC) and I am looking at the interface trap density with respect to temperature (range 300K to around 600K) and also photonic excitation with hv<Eg. That said, i have a question regarding the temperature dependence on...
  6. S

    What's the Difference Between Ordinary and Degenerate Semiconductors?

    whats the difference between ordinary semiconductor and degenerative semiconductor?
  7. L

    What is a process corner and why does it impact semiconductor speed and quality?

    What exactly is a process corner. Is it actually the corner on the silicon wafer? Why does speed vary in process corners? Is the doping not uniform?
  8. P

    Understanding the Hall Effect in Semiconductors

    Homework Statement There are 4 questions in the assignment. None of them need calculation. The questions is as attached below. Homework Equations None. The Attempt at a Solution 1. I think the "photoconductivity" is a typo, should be replaced with "photoconductor". From Wiki, I...
  9. K

    Quantum-Dot Fluorescence - Hypothetical Semiconductor

    Homework Statement Consider a hypothetical semiconductor with band gap 1eV, Relative electron mass is 0.05 and relative hole mass is 0.5. In a cube-shaped quantum dot of this material with side length L = 3nm, what is the energy associated with a transition from (2 1 1) electron state to...
  10. M

    Indirect band gap semiconductor doubt

    indirect band gap semiconductor doubt its said that indirect band gap semiconductors like silicon and germanium are not used as a light sources because they have more non-radiative recombinations rather than radiative ,which inturn decreases efficiency of optical source. but i want to...
  11. mbrmbrg

    Semiconductor: Solid-source Diffusion

    Homework Statement You use the solid diffusion source wafers PH-950 from St. Gobain (see data sheet on TSquare, Diffusion Chapter) to form phosphorous-doped resistors in a p-type wafer with a background doping concentration of 1015 cm-3. According to the data sheet, a 60-min predeposition at...
  12. M

    Is Mass Action Law Only Applicable to Semiconductors at Thermal Equilibrium?

    is mass action law only applicable to semiconductor at thermal euilibrium and why? [FONT="Arial Black"][SIZE="4"] i don't know what happens with semicounductor at thermal euilibrium...why is mass action law not applicable at non-euilibrium...
  13. mbrmbrg

    Semiconductor: Cz Crystal Growth

    Homework Statement A Czochralski growth process is begun by inserting 1000 moles of pure silicon and 0.01 mole of pure arsenic in a crucible. For this boule, the maximum permissible doping concentration is 1018 cm-3. What fraction (X) of the boule is usable? (k=0.3) Homework Equations...
  14. N

    Calc Conductivity of an intrinsic semiconductor

    Calculate the conductivity of an intrinsic semiconductor at room temperature and from the following data: (n)Carrier density(where electron=holes)=2.9*10^19 carrier/m^3 Electron mobility = 0.45 m^2/V s Hole Mobility = 0.23 m^2/V s (q)Charge per electron/hole = 1.6*10^-19 coulomb/carrier...
  15. S

    What Do the Terms in the Semiconductor Density Equation Represent?

    Homework Statement Having some trouble with the following equation, I'm not sure what each term represents. The problem I have is does c,v have something to do with conduction and valence? But what is N and m? And what does it mean when terms are separated by a comma? Homework...
  16. T

    Solving Semiconductor Prob: Get Help Now!

    Hello all ! I'm trying to solve a problem (link below) i have a problem to define the energy(s) distance {exp numerators} so i can't insert to the values needed into the equ. i wrote down. any help would be great ! http://rapidshare.com/files/406858775/ex3.pdf" TNX !
  17. U

    What goes on in a semiconductor.

    Hi Everyone! There are some things about semiconductors that have always puzzled me,and I think it's high time I got them cleared up! Here are my four questions...please help. 1. When an impurity atom (dopant) is added to an intrinsic semiconductor,(say germanium),is the band structure...
  18. G

    Programs PhD in Semiconductor Theory: Recommended Schools

    I'm interested in doing a Phd in semiconductor theory. Where would you recommend?
  19. R

    Carrier transport in semiconductor

    Homework Statement in Intrinsic GaAs,electron and hole mobility are 0.85 and 0.04 meter square/volt-sec and corresponding effective mass are 0.068m and 0.5m, where m=9.11*10^(-31)kg. band gap energy is 1.43 eV at 300K. ---calculate intrinsic carrier concentration(!) and Conductivity. Homework...
  20. R

    What makes a semiconducting material a semiconductor?

    what really makes a semiconductor? Is it just the presence of a band gap but then insulators and metals also have band gaps or carrier concentration? Or we need to perform Hall measurements and also need to study I-V characteristics? Or do we need all of these parameters to establish a material...
  21. M

    Doubt in semiconductor diode theory ?

    doubt in semiconductor diode theory ? hello friends :smile:... in this picture diode is forward biased. positive terminal of battery repel holes n negative repel electrons , finaly electrons n holes recombine n eliminate each other. but its said that current flow is due to electrons ...
  22. C

    Measuring conductivity of a semiconductor

    I'm wondering how one would go about measuring the conductivity of a semiconductor with variation in temperature, I assume the non ohmic behaviour prevents one from making simple voltage current measurements and then inferring resistance and the conductivity...any answers much appreciated...
  23. H

    Comparing Atomic Gas and Semiconductor Lasers

    Hi, I want to know what the important quantitative differences between the light produced by an atomic gas laser and that produced by a semiconductor laser are? I know that produced my atomic gas lasers are low power but high collimation, but semiconductor lasers seem to have higher power...
  24. H

    Atomic gas and Semiconductor Lasers.

    Hi, I want to know what the important quantitative differences between the light produced by an atomic gas laser and that produced by a semiconductor laser are? I know that produced my atomic gas lasers are low power but high collimation, but semiconductor lasers seem to have higher power...
  25. S

    Notation for semiconductor alloy

    Hi - just a quick question on notation. Take, for example, InxGa1-xAs . What is x? Thanks.
  26. M

    Calculating Carrier Concentration in Semiconductors Using the Hall Effect

    A question on semiconductors. I need to determine the carrier concentration and type. I have worked out the type but its the conc. that is getting me. I have the conc., n, as: n = wBJ / eV w is the width of sample, B the mag. field, e is charge, and V the Hall...
  27. L

    Whats the difference between a vacancy and a hole in semiconductor physics?

    hi, I am reading my notes on semiconductor physics and this is a concept that is puzzling me - i always thought a vacancy and a hole were the same thing. in my notes it says that a hole has the same properties as a full band with one vacancy and so for consistency the hole must have...
  28. F

    Band bending in a thin film semiconductor

    Hello! There're very thin (4-15 nm) semiconductor films (passive film) formed on stainless steel by electrochemical method. In a electrochemical cell, I applied potential on stainless steel electrode to adjust Fermi level of the semiconductor passive film. I think that band bending take place...
  29. C

    What Determines the Magnetic Field Orientation in a P Type Semiconductor Coil?

    P type semiconductor coil... The magnetic field orientation in a P type semiconductor wire, in which a DC current is flowing will be caused by the direction of movement of the electrons or the positive holes?
  30. M

    How to experimentally determine whether have adirect or indirect semiconductor?

    Suposse you have a material you are told is semiconductor, but don't know any more history about the material. What experiment(s) can be performed in order to find out if your material is direct or indirect?
  31. P

    Analysis of Lorentz Force in Semiconductor

    I have a few questions about this effect. If I have some semiconductor of N type in which I have electrical field in x direction, and magnetic field in z direction \vec{E}=E\vec{e}_x \vec{B}=B\vec{e}_z Then Lorence force is in the -y direction because in N type of semiconductor n>>p so...
  32. F

    QM - Etop of electron distribution of a semiconductor

    Homework Statement I'm trying to find energy level above Ec where electron distribution makes a peak for a nondegenerate semiconductor. For this case we may take GaAs having Eg = 1.42eV at T = 300K. Homework Equations m_e=single isotrophic effective mass or m_0 energy states, g_{c}(E) =...
  33. S

    Why does the resistance of a semiconductor decrease with increasing temperature?

    Homework Statement The resistance of a semiconductor decreases rapidly with increasing temperature. The main factor contributing to this effect is the rapid increase, with increasing temperature, of a. the speed of the random motion of the free charge carriers b. the concentration of the...
  34. T

    Is There a Semiconductor to Regulate High-Voltage Super Capacitor Output?

    Hi, I have a super capacitor that is charged at 100,000+V at 0.1uF. Naturally it wants to give of its energy instantaneously in a spark; but I am trying to find a compound or semiconductor that can regulate the output of electricity from this capacitor without wasting the majority of the energy...
  35. H

    Need Solution manual for Semiconductor Devices Physics and Design

    Hi Guys, I'm not sure that this is the right place to ask for it, and the thread may be moved to another section, but do anyone have the solution manual of : Semiconductor Devices Physics and Design not Physics and Technology I am despratley trying to solve a homework that questions...
  36. N

    Non-equilibrium states in Semiconductor

    Just to clarify - non equilibrium states in semiconductor means that the semiconductor is affected by external factors such as light?
  37. N

    Carrier Mobility of a semiconductor

    Eg) Silicon Material When we say about mobility of a semiconductor - we basically have to consider its properties etc. One of it is impurities. Here we have to consider its TOTAL Dopant Concentration?
  38. J

    What is the difference between a solid state relay and a semiconductor

    What is the difference between a solid state relay and a semiconductor contactor? Can both switch ac loads? This a link to a company that distinguishes between the two. http://library.abb.com/global/scot/scot209.nsf/veritydisplay/da7ec357f6a7461cc12573ad004e1e83/$File/2CDC110004C0205_07.pdf
  39. S

    Learn the Basics of Semiconductor Laser Operation

    I am curious about the operation principles of semiconductor lasers, but I never had the chance to go through the basic flow. I'd be grateful if someone posts a brief description of how the light amplification is achieved in simple terms.
  40. K

    Is there a rating system for semiconductor manufacturers and distributors?

    I'm looking for a way to get accurate opinions, experiences and recommendations from others in industry on the quality of different electronic suppliers. Specifically, I want to know the quality of the suppliers of MCUs. What are your experiences with Freescale, Renasas, Microchip, Infineon...
  41. Y

    Doped semiconductor, donor electron radius

    hi folks, almost done my semester of physics. this problem has my goat, can't quite figure it out. Done web searches endlessly, but most of the links are pdf articles that I can't access. Homework Statement A donor electron moves in doped semiconductor, for which ε/ε0 = 17.9 and m* =...
  42. N

    Ideas or research topics in semiconductor devices and device physics

    hi I am doing my Electronics and Communication Engineering..I need a topic for paper presentation.Im more interested in semiconductor devices and device physics..It's like,i would like to address any physical limitation in the existing technology in reducing chip size.(this is the only topic i...
  43. A

    Pollution from semiconductor fabrication

    I read about the closing of GMT's semiconductor fab (that happened in 2001) because it was on the EPA's list of hazardous waste sites and that made me wonder, both historically and now what pollution has come from semiconductor fabrication?
  44. B

    Fermi velocity in a non-degenerate semiconductor

    Hi, Ok, so let's say we have a non-degenerate n-type semiconductor such that the Fermi-level/chemical potential is somewhere in the bandgap (probably needs to be low temperature). Typically in a metal you would say that the Fermi velocity is \hbar k_F/m_e. But since the Fermi-energy is below...
  45. M

    Is My Metal Sample a Conductor or Semiconductor? Discover with This Experiment

    You are given a piece of metal of one square cm area and 10cm long. You do not know whether it is a conductor or a semiconductor. Devise some experimental setup to know the nature of the material.
  46. Y

    How to get the semiconductor alloys parameters?

    I'm working on some calculations on Al0.35Ga0.65As & In0.65Al0.45As. Someone can tell me where i can find the elastic/piezoelectric/dielectric constants for these rare alloys?? A database for them exist for us to search?? Thx...
  47. G

    Charge density and potential in a semiconductor

    Couple of electricity questions here. 4. (a) Show that in a steady state, any isotropic material that obeys Ohm’s Law contains no regions with net charge. (b) In certain types of anisotropic materials, the conductivity  is not a scalar but instead a tensor that can be represented as a...
  48. K

    Semiconductor Optical Amplifier Static and Dynamic Design

    Hie. I would like to know anyone who knows or have idea on design static and dynamic model for Semiconductor Optical Amplifier? Currently my lecturer ask me to design using Optisystem software which I quit blur on designing this models. Anyone who knows and help me please. Thanks in advanced..
  49. K

    Polarization dependace of semiconductor optical amplifier (SOA)

    Hi, could you explain me polarization dependence of SOA amplifiers. and how to transfer the transverse electric (TE) mode to transverse magnetic (TM) mode. Are there any passive components to do it?
  50. S

    Hand-on semiconductor demonstration

    I am a graduate student working in semiconductor physics. I have been asked to give a presentation to high school girls about my field. The problem I am running into is that the organizers would like me to provide something hands-on that the girls can do relating to semiconductors. I have not...
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