Prophet Input File

Prophet is quite flexible, and for specialized applications the input files may be quite varied. However, for typical mainstream device simulation applications, the input file usually consists of the following main sections:

• Include files: Include files are typically used to access pre-defined, pre-tested systems of equations. Problems that do not need specialized physics should use these pre-defined systems for convenience.
• Substrate grid and deposited layers: The extent of the semiconductor substrate is defined, along with the vertical and horizontal grid spacing. Following that, layers above the substrate (e.g., oxide or poly) are defined with ``deposit'' commands.
• Doping profile: The doping profile is defined either by analytic expressions (e.g., Gaussian or constant ) or by numerical profiles read in from a file.
• Electrodes: The location of the device electrodes are defined with ``boundary'' commands.
• Initial solution: The initial solution at zero applied bias is obtained using a ``bias'' command.
• I-V curves: The applied bias on the device electrodes are swept over the desired range using ``bias'' commands.
• Save output: The results of the simulation can be be displayed (using ``graph'' commands) or saved for later analysis (using ``graph'' or ``save'' commands).

The Prophet input file on the next two pages illustrates these main components listed above.

Example Prophet input file: MOSFET with polygate (continued on next page):

#
# Include statements define systems of equations to solve
#
include(silicon_poisson)
include(silicon_dd_lombardi)
#
# Define substrate grid, deposited layers
#
grid dim=2
+ xloc=0.00000,0.0010,0.010,0.10,0.4;
+ xdel=0.00005,0.0005,0.001,0.01,0.05;
+ yloc=-0.1,-0.065,-0.06,-0.030,-0.020,0.0,0.020,0.030,0.06,0.065,0.1
+ ydel=0.01,0.005,0.0025,0.0025,0.005,0.005,0.005,0.0025,0.0025,0.005,0.01
deposit mat=oxide thick=0.002 xdel=0.0005
deposit mat=poly start=-0.045 end=0.045 thick=0.0,0.001,0.01,0.1
+ xdel=.0001,.0005,0.001,0.02
deposit mat=oxide start=-0.060 end=-0.045 thick=0.0,0.001,0.01,0.1
+ xdel=.0001,.0005,0.001,0.02
deposit mat=oxide start=0.045 end=0.060 thick=0.0,0.001,0.01,0.1
+ xdel=.0001,.0005,0.001,0.02 zipper
#
# Define doping profile
#
field set=nstip val=1e20*gbox(X,0,0.01,0.003)*gbox(Y,-0.1,-0.042,0.003) mat=silicon
field set=ndtip val=1e20*gbox(X,0.0,0.01,0.003)*gbox(Y,0.042,0.1,0.003) mat=silicon
field set=ns val=1e20*gbox(X,0.0,0.018,0.008)*gbox(Y,-0.1,-0.08,0.008) mat=silicon
field set=nd val=1e20*gbox(X,0.0,0.018,0.008)*gbox(Y,0.08,0.1,0.008) mat=silicon
field set=npoly val=1e20 material=poly
field set=nsubstrate val=-1e18 material=silicon
field set=netdope val=npoly+nsubstrate+ns+nd+nstip+ndtip
#
# Define electrodes
#
boundary xmin=0.01 xmax=0.03 ymin=-0.1 ymax=-0.1 name=source
boundary xmin=0.01 xmax=0.03 ymin=0.1 ymax=0.1 name=drain
boundary xmin=-0.102 xmax=-0.102 ymin=-0.045 ymax=0.045 name=gate
boundary xmin=0.4 xmax=0.4 ymin=-0.1 ymax=0.1 name=back

Example Prophet input file: MOSFET with polygate (continued):

#
# Initial solution at zero bias
#
bias initial system=silicon_poisson
bias system=silicon_dd_lombardi elec=gate voltage=0.0
#
# I-V curves
#
bias system=silicon_dd_lombardi elec=gate vstep=0.1 nstep=6
bias system=silicon_dd_lombardi elec=drain vstep=0.1 nstep=12
bias system=silicon_dd_lombardi elec=gate vstep=0.1 nstep=6
bias system=silicon_dd_lombardi elec=drain vstep=-0.1 nstep=12
#
# Save I-V data to file in column format
#
graph iv outfile=mos.iv