How to realize phosphorus diffusion to silicon in Sentaurus Process?

[Max_spb]

Hi all,
I am writting my diploma about TCADs and have a problem in a practical part.
I must simulate mosfet. And I have a process list of the real one.

I use Sentaurus Process.
And I don't know how to realize phosphorus diffusion to silicon(to generate source and drain regions) with 5e19 concentration, 900C temperature and 10 min.

Silvaco uses:
diffus time=10 temp=900 c.phos=5e19
and that's all,so easy...
But on sprocess 'diffuse' command haven't got any params for arbitrary material(phosphorus), only O2,H2O,N2 and some another.
gas_flow works with they only too.

I know, that it is trivial question, but I am novice.
Please,help!

P.s. Sorry for my English I am from Russia Wink

 

[sudheer_k_m]

Re: Easy TCAD question

use ligament
u do't need to remember the sytax
graphical input

code will be generated

 

[ffaj]

Re: Easy TCAD question

friend, will u help me to learn silvaco TCAD. i have 2005.07 windows version.
will you please send me the tutorial to study.

i am basically a teacher of SOLID STATE devices modeling. please help me to start with TCAD.

 

[timof]

Re: Easy TCAD question

The most common way to introduce impurities into semiconductor is ion implantation, followed by a diffusion step (to anneal the damage). Why don't you specify ion implantation step first, then diffusion?

Are you really using drive-in diffusion of impurities from gas into solid state in your process?

 

[Colbhaidh]

Re: Easy TCAD question

First you should get the phosphorous into the silicon, probably by implantation.
So the statement would be something like

Implant phosphorus dose=1.0E16 energy=35 tilt=0

You will have to adjust the dose energy values to get to your final value but around 1.0E16 dose should result in 1E19. This will come before the diffuse statement.
The the thermal activation and diffusion of this implanted phosphorous is realised by the diffuse statement. The O2, N2,H2 etc is the ambient for the diffusion process and should not need to know about the phosphorous which is already in the silicon. For diffuse with N2, this means a non oxidising thermal anneal process which should be used.
So

diffuse temp=900 time=10

will default to a N2 ambient. This is all you need to thermally activate and redistribute the phosphorous as the TCAD program will do this for all impurities currently in the simulation (in the mesh). Note that the diffusion time is normally in minutes, so if you simulate a rapid thermal anneal, say 1080 deg C for 30 seconds, this will become

diffuse temp=1080 time=0.5

This would be the case for source drain implant and thermal activation. For earlier processes, for example the channel implants prior to gate oxidation, that will use the gate oxidation thermal cycle to activate and redistribute the impurities:

implant boron dose=3.5E12 energy=20 tilt=7 #implant low energy boron at 7 degrees

diffuse temp=850 time=45 H2O #Wet oxidation

The H2O tells the simulator that the oxidation is a wet ambient, therefore will oxidise faster and any exposed silicon will grow an oxide on its surface depending on the time, temperature and any existing oxide on the surface before this simulation step.

Hope this helps ...........

 

[hafed]

Easy TCAD question

Hi All,

How can I simulate with TCAD at different temperature (mixed mode).

Many thanks for help

 

[kannadassan]

Easy TCAD question

Friends, I'm trying Ta2o5 as gate dielectric material. How I can define in TCAD?