In source drain doping concentration may be 1e20 or so. If your substrate is p-type then it should be n-type and vice versa, it can be uniform too.

I you are asking for syntax, I don't have any idea.

Mojtaba Saeedi, The syntex for this should be

doping uniform conc=1e20 n.type/p.type number=region no. (i.e.1/2/3)

suppose you want a uniform  n type doping of 1e20 in source region which is region no. 3 in your code then syntex must be

doping uniform conc=1e20 n.type number=3

Dear Mojtaba Saeedi 

Yes you can use that code but I would like to suggest you to go for Gaussian doping if you are using Atlas it would give you more accurate results.

With regards

Dhanu Chettri