MOS Capacitor and MIM Capactor where to find them?

[kitepassion]

Hi to all,

I am trying to find some DISCRETE MOS Caps and some DISCRETE MIM Capacitors. Even if they are not discrte but at least accessible from the external pin.

Do you know if they exist??

Thank you in advance

 

[erikl]

DISCRETE MOS Caps: AFAIK no - they would be too sensitive against overvoltage
DISCRETE MIM Caps: Yes: all film caps are MIM caps!

 

[kitepassion]

DISCRETE MOS Caps: AFAIK no - they would be too sensitive against overvoltage
DISCRETE MIM Caps: Yes: all film caps are MIM caps!

Thank you for the prompt answer.

My guess is still to have MIM caps with SiO2 layer. Do you know if some exist?

 

[mtwieg]

Well yes, I suppose practically all off the shelf caps are technically MIM. But I'm not aware of any that use SiO2. After all, it's a really poor choice compared to practically all other options for discrete caps. As for a MOS cap, you could just use a FET with its source and drain tied together.

 

[kitepassion]

Well yes, I suppose practically all off the shelf caps are technically MIM. But I'm not aware of any that use SiO2. After all, it's a really poor choice compared to practically all other options for discrete caps. As for a MOS cap, you could just use a FET with its source and drain tied together.

This is true but I need a quite big cap.. such 10uF I don't think it exist a MOS with so high capacitance.. Isn't it?

Thank you again!!!

 

[erikl]

... 10uF I don't think it exist a MOS with so high capacitance.. Isn't it?

Of course not: you can't roll them up in coils like the MIM caps; the "O" means glass!

And you probably wouldn't like to pay for a 17x17(mm)² MOS chip in a 32nm process (tox=1nm ; Vmax=1V) ;-)

 

[dick_freebird]

There are of course some MOS caps you could get, but
they will go by other names. For example, FET-quad
"passive" mixers are nothing but 4 zero-VT FETs that
are sized for ~ 1 ohm on resistance and the LO+, LO-
terminals will be the two pairs of gates; the other
terminals are sources / drains.

You can also get discrete low- to medium-voltage
MOSFETs and get nF-range Cgg.

If your interest is just learning / experimental, CV
curves and so on, these might do as a test article.
But for real applications that need performance at
price, the last thing you want is to make a cap
using high end semiconductor equipment. Unless
you're already headed down that tube in which case
it's a freebie or an incremental mask, depending.

 

[kitepassion]

There are of course some MOS caps you could get, but
they will go by other names. For example, FET-quad
"passive" mixers are nothing but 4 zero-VT FETs that
are sized for ~ 1 ohm on resistance and the LO+, LO-
terminals will be the two pairs of gates; the other
terminals are sources / drains.

You can also get discrete low- to medium-voltage
MOSFETs and get nF-range Cgg.

If your interest is just learning / experimental, CV
curves and so on, these might do as a test article.
But for real applications that need performance at
price, the last thing you want is to make a cap
using high end semiconductor equipment. Unless
you're already headed down that tube in which case
it's a freebie or an incremental mask, depending.

It is incredible! You centered the problem... I want to perform CV measurement in order to have info on the Qox Qit etc... so all the charge in the oxide..
And your suggestions are very helpful. Btw you maybe know some vendors who are interested in.. ('test article' argumentation)

 

[h_vogt]

http://www.ipdia.com/index.php?page=home

 

[kitepassion]

There are of course some MOS caps you could get, but
they will go by other names. For example, FET-quad
"passive" mixers are nothing but 4 zero-VT FETs that
are sized for ~ 1 ohm on resistance and the LO+, LO-
terminals will be the two pairs of gates; the other
terminals are sources / drains.

You can also get discrete low- to medium-voltage
MOSFETs and get nF-range Cgg.

If your interest is just learning / experimental, CV
curves and so on, these might do as a test article.
But for real applications that need performance at
price, the last thing you want is to make a cap
using high end semiconductor equipment. Unless
you're already headed down that tube in which case
it's a freebie or an incremental mask, depending.

Zero Vt mos... are REALLY interesting I've never heard of them before!