Questions tagged [solid-state-devices]
Refers to solid devices built on silicon wafers or ceramic substrate. Materials used could be silicon, germanium or gallium arsenide with copper conductors and oxide based insulators. Doping is the addition of performance enhancements compounds such as gold or germanium. Includes transistors of all types and logic, analog and special purpose devices such as CCD sensors. When done devices are sealed with plastic or ceramic compounds.
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Why does it seem like the ideal photodiode model leads to a violation of conservation of energy?
Short version of my question:
Roughly speaking, the output power from a properly biased ideal photodiode feeding a resistor is quadratic with the optical input power, with seemingly no limit. So at ...
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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) ...
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Why does light doping imply a large temperature coefficient?
In a discussion about how one can make integrated resistors in a given IC technology, Gray, Hurst, Lewis, and Meyer (Analysis and Design of Analog Integrated Circuits) remark that if we want to use a ...
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Limit of applicability of "quasistatic"/capacitive picture of devices
When analyzing the transitories associated with switching in semiconductor devices, in textbook treatments one often sees the time dependence considered by including (potentially nonlinear) capacitors ...
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Why doesn't side diffusion raise resistance of an integrated resistor?
Consider forming an integrated resistor by diffusion of n+ dopants down into some p- substrate (the corresponding pn junction is reverse biased during operation). Let \$W,L,t\$ be the width, length, ...
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How on Earth can a solid state relay be constructed?
Relays are very handy components. Relays allow current to both directions on the controlled load circuit so they can be used for both AC and DC. However, relays have a finite lifetime if connected/...
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Why are drain and source not actually perfectly symmetric?
In textbook treatments, one has that the source and drain of a MOSFET are completely symmetrical and therefore interchangeable -- the distinction is only made by which is at a higher voltage in the ...
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On different well processes (reasons)
My textbook (Weste and Harris's CMOS VLSI Design) is trying to explain to me the difference between n-well, twin-well, and triple-well processes. My question here is about the reasons why we want to &...
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Justification for equivalent gate capacitance simplification in digital circuits
A MOSFET is, in reality, a four-terminal device with capacitances between each pair of terminals:
These capacitances are, of course, the standard MOSFET intrinsic and extrinsic differential ...
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Why do we usually operate well into strong inversion?
In textbooks like the venerable Gray and Hurst or in contexts like my introductory analog design class, it was always emphasized that with MOSFETs we always want our designs to obey some constraint ...
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Do LEDs turn on because of heat? [duplicate]
I was watching one of my seniors soldering a few SMD LEDs on one of his power converters. He touched the iron on the anode of one of the LEDs and it glowed. I think it is because of thermal generation....
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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 ...
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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 ...
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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 ...
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Does \$\phi_{bi}\$ depend on applied voltage in non-uniformly doped junctions?
Consider a linearly graded junction
$$N_D - N_A = ax$$
for some grading constant \$a\$.
Using the standard simplifying assumptions one finds that the depletion region extent is
$$x_{SCR} = \left[\frac{...
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