Graduate Dielectric loss of SiO2 layers.

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Dielectric loss values for very thin SiO2 layers in the GHz frequency range are difficult to find, as they vary significantly based on the deposition method and fabrication process. Standard SiO2 deposited through techniques like e-beam can exhibit a loss tangent around 10^-4, indicating considerable loss. Comparatively, alumina is noted to have lower losses and is often used in high-frequency applications like radomes. Specific values may not be readily available in tables but can be found in foundry specification sheets. Understanding the deposition process is crucial for determining the dielectric properties of SiO2 layers.
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Hello everyone,

Where can i get dielectric loss values of very thin SiO2 layers (nm) at high frequency range (GHz).?
i.e SiO2 oxide layer dielectric loss of MOS (metal-oxide-semiconductor).
I searched a lot on net but i didn't find any useful result, any reference is greatly appreciated.
 
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kpsr said:
Hello everyone,

Where can i get dielectric loss values of very thin SiO2 layers (nm) at high frequency range (GHz).?
i.e SiO2 oxide layer dielectric loss of MOS (metal-oxide-semiconductor).
I searched a lot on net but i didn't find any useful result, any reference is greatly appreciated.
Alumina is used as a high quality radome at GHz frequencies on spacecraft etc so I am sure the losses of a thin film will be quite negligible. Antenna Designers Handbook, (Vol 1 or 2) Edited by Rudge, I think talks about alumina as a window material.
 
tech99 said:
Alumina is used as a high quality radome at GHz frequencies on spacecraft etc so I am sure the losses of a thin film will be quite negligible. Antenna Designers Handbook, (Vol 1 or 2) Edited by Rudge, I think talks about alumina as a window material.
Apologies, wrong material (!) but I suspect it is very similar.
 
It depends quite a lot on how the SiO2 is deposited and the rest of the fabrication process so it is not something you can easily look up in a table, it is more the kind of thing you might find in a foundry spec sheet. "Normal" SiO2 deposited using e.g. e-beam is quite lossy. I'd say 10^-4 would be a reasonable guess for the loss tangent.

tech99 said:
Apologies, wrong material (!) but I suspect it is very similar.

Alumina can easily be an order of magnitude better than SiO2, but again it will depend on how it is deposited,
 
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