how to get the critical field

[plldesign]

it is for the 0.18um CMOS technology
in a formula, it requires to know Ec, the the critical field.
however, the model file does not contains such parameter.
so i have to calculate that value from those known params.
i want to know how to do that.
thanks.

 

[sreechoudhary]

in some books you will get critical feild Vs mobility by using that curve u will surely get critical feild

Added after 3 minutes:

normally the value of critical feild is 5Mv/cm ,i think