Semiconductor Definition and 347 Threads

Typically, I should ask an expert in photolithography about this, but, there are barely photolithographic engineer in our department so I decided to ask experts here. Where do you usually buy a reliable photoresist, what company in particular?

How do you go about calculating electron densities, especially when impurities are involved?

Hi there Im working in a solid state lab I have a semiconductor, let's say 'AB' nowim trying to dope it with a new element 'C' to form 'AB(1-x)Cx' im using bridgman technique for this purpose,,,that is heating all the ingredients together now the problem is that the element C sublimates before A...

The book I'm reading is discussing the physics of semiconductors. I'm having a hard time understanding a passage in section introducing n-type semiconductors. (Phosphorus is used as the impurity) The book says: "At normal operating temperatures, this extra electron breaks its bond with the...

Hello pf Is the effective mass dependend on the donator atom in a semiconductor? In our experiment we have calculated the effective mass in a germanium semiconductor, doped with an unknown atom. It is 0.39m_e. From the internet we know that the effective mass is 0.33m_e. Is our result...

I am interested in simply simulating in MATLAB or an open source software, the following qualitative explanation of the band theory. I want to show to an undergraduate course maybe a simple applet with the difference between semiconductor (Si) and insulator (Diamond for example) . do you have...

Hi, How can I prove direct band gap property of a Transition Metal Dichalcogenide electrically and optically through experimentation? I can use PL measurements to prove this for optical band gap. Is there any other equipment or technique to prove this? I can not use ARPES because channel length...

Homework Statement Can anyone explained to me the factor of 2 in the equation for the intrinsic carrier concentration? Homework Equations ni is proportional to exp(-Eg/2kT) where ni is the intrinsic carrier concentration, Eg is the band gap energy, k is Boltzmann's constant, and T is...

Please check the following questions. Steady state of semiconductor w.r.t excess carrier. 1. If we shine photons on semiconductor and then turn the light off, semiconductor is not under the steady state condition. (it is under transient state since excess carrier concentration is decreasing)...

What is the difference between a "good" and a "bad" oxide?

http://ecee.colorado.edu/~bart/book/book/chapter2/ch2_6.htm#2_6_2 equation (2.6.24) we have this equation for fermi level, but I wonder how this works though? In the lecture, we assumed Ec=Eg and Ev=0 to get E_gap/2. but I wonder how (Ec+Ev)/2 actually gives E_gap/2 instead of Ec-Ev=Eg

Homework Statement A sample of germaium has an acceptor concentration of Na=10^17 and a donor concentration of Nd=0. Calculate the intrinsic carrier concentration, majority carrier concentration, and Ef-Efi. Use T=400 Homework Equations No*Np=ni^2 Nv=Nv*(T/300)^3/2 Nc=Nc*(T/300)^3/2 ni^2=Nv*Nc...

Homework Statement Si atoms get doped inside GaAs to a concentration of 1.5*10^8 . Assume that the silicon atoms are fully ionized and that 35percent atoms replace gallium and that 65% of the added atoms replace arsenic t=300k Fnd the acceptor and donor concentrations Calculate electron /...

Homework Statement The question is in the picture attached. When Na=0, that means the acceptor concentration(i.e. open holes?) is zero? Homework Equations (Nd-Na)/2 + sqrt((Nd-Na/2)^2+ni^2) (Na-Nd)/2 + sqrt((Na-Nd/2)^2+ni^2) The Attempt at a Solution Solving for Nd=10^8: majority carrier =...

I'm not good at English. I'm a undergraduate student. I'm interested in this research. I'm interested the simulation part but I don't know how to start. Please guiding me how to simulate method or program did they use on paper. " A Theoretical Study on Van Der Pauw Measurement Values of...

Homework Statement In my book ,I found this line which says ,"The collector current comprises two components-the majority and the minority carriers .The minority-current component is called the leakage current and is given the symbol ##I_{CO}## .The collector current, therefore is determined in...

What is Dielectric confinement effect?. or could you advise me literature about this? Thank you.

For Mass action law to hold for extrinsic material in equilibrium, If n goes up and p goes down for an N-type material then overall carrier concentration is the same (equal to ni_square). So why does an N-type material conducts better than a an intrinsic semiconductor (presumably they have same...

Can someone give me a clear, nonambiguous definition of the fermi level in a semiconductor? Is it the energy of the highest occupied state, the chemical potential at T=0 or what? I don't think it is the first since the fermi level is typically put midway between the conduction and valence band...

Hi, I understand that a n type doping will increase the number of electrons, and those electrons will go to the conduction band since the valence band is already filled. I don't exactly understand the effect on the bandgap. Thanks!

I know we can shift the fermi level by doping the material with other elements. In case of semiconductors doping with the pentavalent or trivalent will change the fermi level. But my question is ''can we shift the fermi level, without altering the position of valence band and conduction band?"...

Why is the conduction band state s-type and the corresponding valence band state p-type?

Can anybody explain my what is the origin of this forbidden gap? I mean how it was created and what is the physics behind this issue?

I am finishing my degree in Mathematics and will be enrolling into a Mathematical Physics program. My goal is to work with Semiconductors. Is this possible to find software that chip design engineers use? I would like to design my own chips with software to build a basic understanding that...

Good day!, today, i visited an Institute about Semiconductor devices, One characterization device (Reflectance Spectrometer) which used to determine the reflectance of the semiconductor materials. This device used Semiconductor detector to detect the reflected light from the sample, but I'm...

Hi Guys, i want to fabricate semiconductor p-type and n-type material and i want it to combine to make a p-n junction diode, but i don't know how to combine or merge the two, (my materials are thin films) I'm thinking to solder it but I'm afraid that it will break, or distort, or I'm thinking to...

Is the no. of electrons on a brand new unused and untested harddisk is different from no. of electrons on a used hard disk completely filled with data. i mean will there be even a change of one electron? Please consider the following points before answering: 1- Does all the electrons from a...

Hi, I am working on CdZnTe detector. Can anyone please explain the function of bias resistor in radiation detector setup & how to select an appropriate bias resistor?

Why is a slab of semiconductor used instead of just a basic resistor. The charge would be pushed to either side by the magnetic field in the same way, would it not?

I was wondering if anyone knows the relationship with temperature and frequency tuning in wide bandgap semiconductors. I just want to know why wider bandgaps have higher temperature tolerance and why does that mean high frequencies can be achieved? Explanation with formulas would be great!

Homework Statement (a) Show law of mass action. (b) Find dopant concentration and hole concentration.[/B] Homework EquationsThe Attempt at a Solution Part(a)[/B] Bookwork. Part(b) Letting the doping concentration be ##D##, we have: D = n - p For ##I = n_{intrinsic} = p_{intrinsic}##, we...

Homework Statement [/B] (a) Explain the terms intrinsic, extrinsic, mobility and effective mass in semiconductors (b) What is a hole and explain its mass and charge (c) Why is mobility of holes often less than mobility of electrons? Find the number density of holes and electrons (d) Find the...

Homework Statement Determine values for beta the constant of proportionality for a semiconductor. Homework Equations Given below. The Attempt at a Solution Im struggling with line 2 to line 3 of the solution. The problem I'm having is I can't see where the squared exponential term has...

Homework Statement we look at a silicum n++ p+ n transistor. given: NE= 1,0×1018 cm–3; NB= 2,0×1016 cm–3; NC = 2,0×1015 cm–3; here E stands for the emitter, B for the basis and C for the collectorHomework Equations a. calculate the distance in eV from the fermi-level to EFi for the emitter...

Taken from my textbook: My understanding is that: One valence electron, 2 spin states -> Half-filled Brillouin zone Seeking inspiration from "Nearly Free Electron Model": gaps open up at zone boundaries States nearer to zone boundaries get pushed down in energy further Since a fermi...

I have calculated the electron transmission function T(E) over a potential step of height V0 using T-matrices. I model a semiconductor heterojunction, which requires different effective electron masses on either side of the step. The wave functions on either side of the step are planar waves...

From some literature, I read the following band structure of the Al doped Si. The explanation offered: "have vacant acceptor levels at energy Ea above the valence band. Electrons from the top of the valence band can be easily excited into these levels." I thought the above explanation is...

I have calculated the electron transmission function T(E) over a potential step using T-matrices. I model a semiconductor heterojunction, which requires different effective electron masses on either side of the step. We have 2 boundary conditions at the step at x = x0: Y1(x0) = Y2(x0)...

sorry, really didn't know where to post something like this. But where can i get a hold of a wire of semiconducting material?

As the atoms of a material are brought closer together to form the crystal lattice structure, there is an interaction between atoms, which will result in the electrons of a particular shell of an atom having slightly different energy levels from electrons in the same orbit of an adjoining atom...

What are the commonly asked questions for the semiconductor process engineer position ? I am assuming cleanroom equipment working principles.. what else? Thanks in advance for your responses.

Hello everyone, I have a quick question about the energy of the silicon. I know that, as a semiconductor, the silicon has an energy gap between the valence band and the conduction band. But according to this image ...

Hello. I'm currently taking a physics course that gives me the freedom to take any subject related to semiconductors and do some research on it, presenting it at the end of the semester. I know I want to do something related to programming, but I'm having a hard time finding a theme. Hence me...

Why is black phosphorus a semiconductor with a direct bandgap? The problem is mentioned by the two following references: "The three bonds take up all three valence electrons of phosphorus,so, unlike graphene, monolayer black phosphorus is a semiconductor with a predicted direct bandgap of 2 eV...

I'm trying to understand how a diode works and for this I've used(among other resources) the book written by Albert Malvino, Electronic Principles. Everywhere I read about this topic, it says that when the N-type and P-type semiconductors are joined together, the free electrons from the N-type...

For a wavefunction at the Brillouin boundary we have: \langle k|H|k\rangle = \epsilon_0 (\vec k) \langle k'|H|k'\rangle = \epsilon_0 (\vec k+\vec G) \langle k'|H|k\rangle = V_G = \frac{1}{L^3} \int e^{i(\vec k - \vec k') \cdot \vec r} V(r) d\vec r \langle k|H|k'\rangle = V_G^* Using...

I understand the difference between p-type and n-type semiconductors but I just don't understand how adding a p-n junction to a circuit affects it. Can someone please explain how semiconductors work? For example, if I had a circuit with just a battery and a light bulb, what would change if I...

When electrons leave the valence band and jump over the gap to the conduction band, what is the density of the remaining holes? If 2.5 electrons/cm^3 leave the VB to the CB, will the density of remaining holes be 2.5 electrons/cm^3? To me it is logical, but I am wondering if mass of electron...

I was wondering if it would be possible to determine if a Schottky diode was n-type of p-type (in the bulk) by only using I-V measurements?

I've been playing around with some ideas of electron-hole pairs in semiconductors lately, have realized that I'm confused about some basic conventions that maybe the physics forum community could help clear up. Let's imagine that we have a direct gap semiconductor initially at zero temperature...