next up previous contents
Next: 3. Device Equations Up: 2.3.3 Devices Previous: 2.3.3.13 Power Monitor

2.3.3.14 Distributed Device

For distributed devices the transport equations have to be solved. Of course it is possible to solve for Poisson's equation alone which is sufficient for the description of dielectric structures with complicated geometries. These devices are treated contact-wise in MINIMOS-NT. Each contact is connected to the rest of the circuit via a zero-valued voltage source. The contact current is part of the solution vector and the constitutive relation for the contact potential $ \psi_{C}^{}$ reads

f$\scriptstyle \psi_{C}$ = $ \psi_{C}^{}$ - $ \varphi_{C}^{}$ = 0 (2.44)

with $ \varphi_{C}^{}$ being the node voltage of the circuit node connected to the device. The stamp is given as

yx, y $ \varphi_{C}^{}$ $ \psi_{C}^{}$ IC f
$ \varphi_{C}^{}$     -1 IC
$ \psi_{C}^{}$ 1 -1   $ \psi_{C}^{}$ - $ \varphi_{C}^{}$
IC        
A detailed description of the calculation of the contact current and an example can be found in Chapter 5.

next up previous contents
Next: 3. Device Equations Up: 2.3.3 Devices Previous: 2.3.3.13 Power Monitor
Tibor Grasser
1999-05-31