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Dielectric thickness TOXE, TOXP and DTOX

#1

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 TOXE
Change TOXP according to TOXE with minimum DTOX.

#2

hi mam, i am akash from amity noida REFERENCE ANU MEHRA MAM, i need your help while doing my project on ngspice, can you please send me screenshot of NAND gate code

#3

Hi Akash,
I have not make a 2 input nand gate.
Below is the connections for 3 input nand gate.

*MOSFETs drain gate source body
Mp1 vout va vdd vdd pmoslp l={len} w={wpmos} ; pmos
Mp2 vout vb vdd vdd pmoslp l={len} w={wpmos} ; pmos
Mp3 vout vc vdd vdd pmoslp l={len} w={wpmos} ; pmos
Mn1 vout va vsrc1 vss nmoshp l={len} w={wnmos} ; nmos
Mn2 vsrc1 vb vsrc2 vss nmoshp l={len} w={wnmos}; nmos
Mn3 vsrc2 vc vss vss nmoshp l={len} w={wnmos}; nmos

Hope it will help
Smita