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Spin on doping to dope SOI wafer

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Dear all,
I don't know if this is the right place to ask this query.
I am currently working with spin on doping process to dope SOI wafer. I have a dopant with impurity concentration of 1e17/cc.
Is it possible to have a higher doping level in the Si (say 5e17/cc) with this concentration?

Thanks in advance
 

Spin on Doping

Only if the solid solubility in silicon is much greater than the carrier
solubility. That is unlikely to be the case with a liquid phase, room
temperature situation.

But I would expect that after spin-on comes a bake which would
remove the liquid carrier and raise the at-surface concentration.

I think you want to determine a "dry" dopant N/cm2 (by area)
and then your volume concentration becomes that number
divided by drive depth; I remember calculating that kind of
thing in my semiconductor physics classes, back in the '80s when
people actually still used dep & diffuse processing.

Surprising to me that anyone uses wet processes for doping
anymore.
 

Re: Spin on Doping

Thank you for your reply.
As far as I know spin on doping technique is till date the best known method for high doped semiconductor. The chance of sample damaging is quite low.

According to the data sheet, we should expect solid solibility in silicon to be around 1e20 at 950°c
Traditionally, two steps are followed in spin on doping technique: predeposition and drive in.

So, do you say in this process I can achieve more than 1e17 impurity atoms in the sample?
 

Spin on Doping

Provided that you can establish a semi-infinite areal dopant density,
you can then drive as much of it into the silicon as you please. The
question is, how much dopant will be available initially and how far
are you going to drive it.

Your "wet" concentration is immaterial, you need to know the "dry"
(pre-dep) quantity.
 

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