All Questions
Tagged with semiconductors solid-state-devices
15
questions with no upvoted or accepted answers
3
votes
0
answers
135
views
High frequency switching applications
I was reading that for high frequency switching applications with
semiconductors, the ratio of the electron to hole mobility should be high.
Why is it so? Is it a necessary condition always? Or ...
- 171
3
votes
1
answer
221
views
Why do PMOS suffer a worse body effect than NMOS?
Gray, Hurst, Lewis, and Meyer give the following discussion around PMOS transistors which I followed except for the sentence which reads:
Good use can be made of this fact in analog circuits to ...
- 1,161
2
votes
0
answers
57
views
How does the stored charge gets decayed when going from forward bias to zero bias?
In a pn junction diode when forward biased, excess electrons and holes get stored in p and n regions respectively.
If we short the diode by connecting p,n terminals with a wire,
how do these stored ...
- 1,150
1
vote
1
answer
100
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Confusion about why pn junction discussion insensitive to doping variations faster than Debye length
Sze (Physics of Semiconductor Devices, 3e) gives the following discussion which relates to how equilibrium electric fields/equilibrium potential build-up at thermal equilibrium are related to doping ...
- 1,161
1
vote
0
answers
246
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Semiconductor mass action law question
I was told that the mass action law $$np = n_i^2$$
only applies to compensated semiconductors and intrinsic semiconductors, and it does not apply to n-type or p-type semiconductors. Is this true? I ...
- 447
1
vote
0
answers
47
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Can anyone properly explain me the characteristic curve of the p-type JFET?
I know how a MOSFET works. But recently I wanted to know details about JFET.
When V(GS) = 0 volts there will obviously a current flowing through the p-type channel. What confuses me is how the ...
- 2,519
0
votes
1
answer
99
views
Process compatibility between a non-planar avalanche photodiode and planar CMOS at 0.130μm process technology node
I plan to integrate a non-planar P⁺⁺/i/P⁺/N⁺⁺ avalanche photodiode (APD) array with a peripheral control circuit (e.g., trans-impedance amplifier, analog-to-digital converter, and quenching circuit) ...
0
votes
1
answer
114
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Understanding thermal instability breakdown in pn junctions
I am currently reading Sze (Physics of Semiconductor Devices, 3e, Chapter 2.4.1) and am trying to understand his discussion of thermal instability breakdown/runaway in pn junctions. I have also ...
- 1,161
0
votes
1
answer
40
views
Energy band diagram of a polar material
For a single piece of a polar material (ex. GaN, AlN, etc), there exists a constant electric field inside the material due to the bound charges at the surface.
Above figure shows the resulting band ...
- 447
0
votes
0
answers
61
views
MOSFET current at very low temperature (4K)
I am trying to model the current at low T. To do so I need to compute the integral between the fermid diract statistic and the conductivity, with respect to energy. My problem is that I cannot ...
- 1
0
votes
0
answers
46
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What is the structure of GaAs?
Ga has three valence electron, and As has five valence electron. How do they share electrons so that each has 8 valence electrons? Does each Ga atom share 5 electrons with 5 different As atoms?
- 447
0
votes
0
answers
27
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direction of current densities for electrons and holes?
Let's say we have:
\$ J_n = 3 \frac{A}{m^2} \$ and \$ J_p = 2 \frac{A}{m^2} \$
and let's define the direction of positive current (flow of positive charges) to be moving from left to right. Then, ...
- 447
0
votes
0
answers
43
views
Short Channel MOSFET model
I was reading on a book (Thomas Lee, The Design of CMOS Radio Frequency Integrated Circuits) that in a short channel model, since the phenomenon of drift speed saturation is very relevant, it is a ...
- 3,550
0
votes
0
answers
215
views
Why is the absorption coefficient (α) not zero for energy of incident photon less than the band gap of the semiconductor?
α ( Absorption Coefficient) tells us about the absorption of a photon by a semiconductor for the creation of electron-hole pairs.
The absorption coefficient increases abnormally as the energy of ...
- 35
0
votes
1
answer
131
views
Temperature-Dependent Electrical resistance Si and SiC
In a power electronics device, it seems that silicon carbide (SiC) has a higher variation of electrical on-state resistance with temperature in comparison to silicon (Si). Does anybody know the reason?...
- 21