I would like to know what those vertical lines mean in this MOS band diagram. These vertical lines are at the intersections of both the metal with the insulator, and the insulator with the semiconductor. Why are they there and what do they mean?

Also, at the intersection of the semiconductor with insulator, all of the band edges, conduction, valence, etc, seem to be joined together with the vertical line. What does that mean? The metal fermi level also joins together with the left vertical line. Again what does it mean? Strangely, they join together at the bandgap, where there are no states available, so how can they just end up there?

Are the vertical lines potential barriers? So that electrons below the insulator conduction band, and above the valence band can't climb the barrier ? And electrons at the insulator conduction band or above can pass thru because they have the required energy? Similarly for the valence band?

Thanks a lot!

 

Did you see this -

https://ecee.colorado.edu/~bart/book/moseb.htm

Then 3 videos show up if you google "fermi energy diagram mos"

And this -

https://nanohub.org/groups/ece305lundstrom/File:Eband_MOSFETs_S15.pdf

Looks like the parallelogram is the oxide layer in your drawing.

M O S Metal Oxide Silicon in the diagram.


Regards, Dana.

 

Did you see this -

https://ecee.colorado.edu/~bart/book/moseb.htm

Then 3 videos show up if you google "fermi energy diagram mos"

And this -

https://nanohub.org/groups/ece305lundstrom/File:Eband_MOSFETs_S15.pdf

Looks like the parallelogram is the oxide layer in your drawing.

M O S Metal Oxide Silicon in the diagram.


Regards, Dana.

Yes i seen all of these. none of them explain what the vertical line are. They just assume the reader knows.

Hence why I came here to ask if anyone can explain that to me.

Still waiting for a reply.... Help!

 

hi ADD,
I have colour coded the vertical line etc.
To which line colours is your query referring.?
E

EDIT:
Look at this link, N MOS Doping
https://www.google.com/search?q=n+m...dAhWKXsAKHebTDiAQsAR6BAgAEAE&biw=1330&bih=894

 

hi ADD,
I have colour coded the vertical line etc.
To which line colours is your query referring.?
E

EDIT:
Look at this link, N MOS Doping
https://www.google.com/search?q=n+m...dAhWKXsAKHebTDiAQsAR6BAgAEAE&biw=1330&bih=894


View attachment 161140

Hi there, its the ones in the band diagram only. Not on the mosfet.

I want to know what the vertical lines in the oxide layer mean. Are they potential barriers?

 

Read page #3 of this PDF.

 

Read page #3 of this PDF.

I already know all that.

I want to know what the vertical lines mean. That is not said.

Gees

 

They represent the molecular interface between the M O S regions ie: the junctions of the different materials,
On paper they are just drawing lines, I don't see why you having a such problem with such an obvious depiction of voltage barriers.?

Do you follow that OK.?

Gees indeed.

Added: edited your image.

 

They represent the molecular interface between the M O S regions ie: the junctions of the different materials,
On paper they are just drawing lines, I don't see why you having a such problem with such an obvious depiction of voltage barriers.?

Do you follow that OK.?

Gees indeed.

Added: edited your image.
View attachment 161154

Hi Eric.

That is interesting. So the fermi and conduction bands split from the metal, through the oxide, until they appear well apart at the semiconductor.

And the metal has a valence band showing as well. Why don't they usually show it on a band diagram? Implicit?

qPhi(zeta) is the energy difference function from the metal Ef and Ec through the oxide? Wow!

OK, so you said the vertical lines are energy barriers. Could you say more about that?

Thanks a lot, that is very helpful!

 

They represent the molecular interface between the M O S regions ie: the junctions of the different materials,
On paper they are just drawing lines, I don't see why you having a such problem with such an obvious depiction of voltage barriers.?

Do you follow that OK.?

Gees indeed.

Added: edited your image.
View attachment 161154

Answer me now Eric!

 

Answer me now Eric!

Good luck getting help with that attitude!

 

Good luck getting help with that attitude!

Good luck trying to figure out jokes!

 

hi,
I guess you know that the interface junctions between the M O S materials are not just physical contact junctions.
They are grown, doped junction and are only few nanometres thick.

The different voltage levels for MOS devices are well documented on the web and there is no point in me retyping that data.

I have found the attached document, which explains the voltage barrier voltages. I hope this will answer your query.
E

Answer me now Eric!

BTW: Could not answer sooner as I was doing an important job, tidying my sock drawer.

 

The way I see it, lets say post in #6, page 3, figure 1.3. The vertical lines on the sides of the white region are the physical edges of that oxide layer, on the X axis. The Y axis represents the potential required to overcome the oxide barrier at left and right side of the oxide.

The same here in 6.2.1 https://ecee.colorado.edu/~bart/book/moseb.htm - see the x axis labeled Position in nm?