While doing my research, I came in a way where I need to play with parameters - TOXE, TOXP and DTOX.
But, before I came across these parameters I didn’t have learn anything about them. Instead I have just learn TOX which is the thickness of dielectric material in nmos/pmos.
In ngspice there was no such parameter tox but new parameters mentioned above. After researching about them I came to the conclusion that:
TOXE is the electrical thickness
TOXP is the physical thichness
DTOX is the difference between TOXE and TOXP (TOXE-TOXP)
Now again the question arises which one to vary to see the effects in the transistors.
In BSIM 480 ngspice manual I observe that the default value of DTOX is 0. This means that the ideal case is when TOXE is equal to TOXP. Larger the difference, bad is the design.
I will do the following steps in order to see the effects of varying TOX:
Change TOXP according to TOXE with minimum DTOX.