Johnny5454 said:
I mean transistors in the CPU, when voltage is applied to the CMOS gate of the transistor (high input) does the gate or another components of a transistor emit infrared radiation inside the CPU and do the neighboring transistors absorb this radiation? thanksdavenn said:Hi there
welcome to PF
not a very clearly written question
what neighbouring transistors ?
Are you referring to multiple transistors on an IC die ?
EVERYTHING above 0K radiates thermal energy, by either radiation, conduction or convection
or some mix of all 3
When voltage is applied to the gate, an electric field is created. Does this field affect the atoms of neighboring transistors? Or do the components of a CMOS transistor emit at least some kind of radiation when a gate voltage appears?Rive said:
for example, a voltage (high input) is applied to the gate of the pMOS transistor inside the CPU, an electric field is created, electrons react to this field, and a p-channel is created. 1. Does infrared radiation occur when the channel opens?Rive said:
for example, at the NOR gate, two pmos transistors are connected in series, when the voltage is applied to the gate of one of the transistors, will the transistor emit infrared photons that will propagate to the neighboring transistor?Baluncore said:
I've never, ever, anywhere seen infrared radiation to be considered as anything important at the range of the components of a (general purpose) integrated circuit: guess the heat transfer capacity of Si limits the temperature difference (thus, the radiation effects) at that scale.Johnny5454 said:
Thanks for the answer, it’s just interesting when the p-channel (pmos) is created, will this channel emit thermal photons, and will these photons reach the neighboring transistors? Or will this channel is warm enough to transfer heat to an adjacent transistor?Rive said:
Johnny5454 said:
Yes. The thermal photons are emitted and this emission is used in the diagnostics of the both digital and power ICs. The radiative heat transport is not effective compared to thermal conduction in semiconductor ICs though - the emissivity of silicon or GaAs is low at thermal wavelengths, while thermal conductivity is close to that of metals. Therefore, nearly all thermal crosstalk effects in ICs are coming from thermal conduction (phonons transfer), not the radiation (photons transfer).Johnny5454 said:
The whole 'photon' thing is seriously misleading in this context. Every piece of material always emits (and absorbs) thermal radiation, what is an incoherent, continuous spectra mixed flow of photons.Johnny5454 said:
Thanks for the answer. I just did not know that radiation also occurs inside the material. And then when the voltage comes to the gate, the conductive channel will radiate more heat than when there is no voltage?Rive said:
Thanks.trurle said:
At normal circumstances, no. If "voltage spread" happens between adjacent nmos and pmos, the destructive "latchup" effect may happen.Johnny5454 said:
Thanks.trurle said:
If it did, that would be a design/layout error.Johnny5454 said:
the electric field is infinite, just the intensity drops, is that right? Is there really such a good isolation between transistors in the CPU that the electric field will not at least slightly affect the neighboring transistors?berkeman said:
You mean "infinite in extent", and sure. But it's a matter of the magnitude of the field -- if it is many orders of magnitude lower than it is inside the transistor, it will not have any measurable effects.Johnny5454 said:
Thermal radiation in CMOS transistors refers to the emission of electromagnetic radiation from the transistor due to its temperature. This radiation can affect the performance and reliability of the transistor.
Thermal radiation can cause an increase in leakage current, which can lead to higher power consumption and reduced speed in the transistor. It can also cause changes in the transistor's threshold voltage and can induce noise in the circuit.
Some common methods for reducing thermal radiation in CMOS transistors include using low-power design techniques, implementing thermal management strategies, and using materials with lower thermal conductivity. Additionally, optimizing the layout and placement of transistors can also help reduce thermal radiation.
Thermal radiation can cause thermal stress in the transistor, which can lead to device degradation and failure over time. It can also cause variations in the transistor's electrical properties, leading to performance and reliability issues.
Thermal radiation in CMOS transistors can be utilized for temperature sensing and thermal imaging applications. It can also be used to monitor and control the temperature of the transistor itself, improving its overall performance and reliability.