
			ELO MOSFET


This example consist of a simulation of a 1.5 micron ELO MOSFET.  This
device is similar to the previous device (psuedo soi).  In this device
the oxide is not only under the source and drain diffusions like the 
previous device, but its also under the the channel.  There are windows in
the oxide to provide the holes a path to the substrate.

The device consists of identical size and mesh as the psuedo soi device.
The mesh is constructed by a file called n3egrid.p2.  The eliminate and
spread statements are still the same.  The region statements define
the oxide locations in the device.  The device is then doped appropriately
and the grid, junctions and the doping contours are plotted.

A file called n3esolve.p2 is used as with the previous device to solve 
the initial gate and drain characteristics.  The mesh as usual is imported
into the file first.  To solve for initial conditions at zero bias, 
the gummel method is used.  The file specifies the surface mobility using
the material card.  The models used in this simulation are concentration and
field dependent mobilities and impact ionization.  The impact ionization 
is not important at low bias but needed at high bias when the fields get
strong.

The initial solution is obtained and an outfile is saved as nbias.init.
Then the method is switched to single carrier newton for the remaining
gate and drain current and voltage characteristics.  A log file is started
to store the data of the simulation.  A solution is first obtained at 
the drain to source voltage of .1 volts and saved in an outfile called
nbias.1.  The gate is then stepped from -0.5 volts to 2.0 volts and the
gate characteristics are plotted.  Next, the drain voltage is raised from
zero to 100 millivolts and the result is saved in a file called
bbL20dv4.100mv.  The gate voltage is then stepped from 0 to 5 volts and the 
result is saved in bbL20d.100mv.  It is good to save some outfiles during
the simulation so that post processing at selected bias points can be done.

A file called n3edrain.p2 is used to obtain the current voltage characteristics in the linear and saturation regions.  This file loads in the mesh and the
initial solution from the past simulation and then steps the gate voltage
up to the desired bias (3V).  The drain to source voltage is then stepped
up to 3 volts.  The drain to source voltage versus the drain current is then
plotted.

