postmini_users_guide_v92.tex

this file is contain important facts aboute different programming langueges.

and $\theta = -45\degrees$.

The following diagram illustrates the polar coordinate system.
You may notice that this is a left-handed coordinate system.
A left-handed system
is used to be consistent with the way 3D plots are displayed by
other workers. In the default view, the source is on the left,
and the drain on the right. Note that this is {\em opposite} from
the way the SURF program displays MINIMOS data.
%%
\mbox{}\\
\epsfxsize 3.5in
\centerline{\epsfbox{spherical_coords.eps}}

On devices that support color, the plot will
be done using color area fill technique. This method plots the surface
in different colors, depending on the ``height'' of the data.
This makes is very simple to determine the actual value of data being
plotted.
A legend is printed on the side of the plot, similar to the
2D color contour map.
On all other devices, the surface will be plotted using a
hidden line removal technique. On color devices, the ``underside''
of the plot will be done in a different color.

On workstations, you can use the mouse to intteractively rotate the 3D plot.
Enter the {\tt O} (orbit) command at the menu prompt.
A box around the 3D plot will appear in the plot window.
Click and release the first mouse button at the right edge of the window
to rotate the plot clockwise.
Click and release the first mouse button at the left edge of the window
to rotate the plot counter-clockwise.
Click and release the first mouse button at the top edge of the window
to move your eye position towards the ``north pole''.
Click and release the first mouse button at the bottom edge of the window
to move your eye position towards the ``south pole''.

If your data is better represented by discrete values, rather than a
continuous function, you can switch Postmini into a mode where it
plots a 3D histogram, rather than a surface. Go to the top level ``Defaults''
menu, and change the ``Default hidden line method'' to histogram.
This will also change contour plots, so that Postmini plots boxes
centered on each data point, rather than interpolating a surface.

The annotation option can be used to interactively add text,
lines, arrows, boxes, symbols and elliptical arcs to the plot.
Text is processed by the ``mathmode'' utility,
which allows you to enter sub and/or superscripts, Greek letters,
and certain math symbols using a subset of the \TeX\ math syntax.
Read section~\ref{sec:mathmode} for details on how to enter
mathmode format strings.
%
\subsection{Comparison plots}
POSTMINI can plot several 1D cross-sections on the same graph.
The 1D slices can be of the same internal quantity, different quantites,
or from different simulation runs. You can also import data files from
different simulators, including 1D ASCII files, for plotting.

To use this feature, select COMPARE at the main menu. You will be put into
a subsystem which has these features:
\begin{itemize}
\item 
Add - Add a curve to the plot list. You will be prompted for
the quantity to plot, the cut line and coordinate (for 2D data sets).
You can also specify plot attributes
such as line type (e.g. solid, dashed), color, and plotting of symbols.
A total of forty separate curves can be plotted at once.

Postmini version 8.1 and higher supports multiple X and Y axes
(earlier versions only supported separate axes from Postmini command files).
You can associate a data curve with either the top or bottom X axis,
and the left or right Y axis. Use the {\tt xaxis\_tag} and {\tt yaxis\_tag}
menu items.
\item 
Barchart - Plot all the data as a bar chart.
\item 
Clear - Delete all curves from the plot list. Useful for ``starting over''.
\item 
Delete - Delete a curve from the plot list.
\item 
Integrate - Integrate a quantity vertically or horizontally,
and add to plot list. This option applies to 2D data only.
\item 
List - List all curves to be plotted, with their labels.
\item 
Modify - Modify various aspects of a curve, such as the plot label,
curve color, linetype, or symbol. You can also modify the scale factors
(AX, AY, MX, MY) that were applied the data, or apply an expression
to the data.
You can also select whether a curve
will be included in the plot. This is useful if you wish to store
a number of data items at one time, but selectively plot the entries.
You can also change the axes the curve will be plotted on.
Postmini supports a top and bottom X axis, and a left and right Y axis.
\item 
Plot - Plot all the data as an X--Y graph.
\item 
Read - Read a new data file.
\item 
Show - List information about a curve
\item 
Exit, quit - Return to main menu.
\end{itemize}

On workstations, you can use the mouse to interactively take a ``sample''
of the plot, and display the X-Y coordinates.
Enter the {\tt S} (sample) command at the menu prompt.
A crosshair cursor will appear in the plot window.
Click and release the first mouse button to take a sample.
The data value coordinates will be displayed
on the menu. You can continue to click the mouse button to sample other
areas of the plot --- the change from the last sample point is also
printed. Press mouse button two to exit sample mode.

On workstations, you can use the mouse to interactively ``zoom''
into a region of the plot.
Enter the {\tt Z} (zoom) command at the menu prompt.
A crosshair cursor will appear in the plot window.
Click and release the first mouse button to define the lower left of the
zoom area. The cursor will now change to a ``strechy'' box, which defines
the area to be zoomed. Click and release the first mouse button
to perform the zoom. Press mouse button two to cancel the zoom.
The unzoom function {\tt U} will rescan all the curves and
pick bounds which will enclose all the data.

The annotation option can be used to interactively add text,
lines, arrows, boxes, symbols and elliptical arcs to the plot.
Text is processed by the ``mathmode'' utility,
which allows you to enter sub and/or superscripts, Greek letters,
and certain math symbols using a subset of the \TeX\ math syntax.
Read section~\ref{sec:mathmode} for details on how to enter
mathmode format strings.
%
\subsection{Overlay plots}
An overlay plot consists of multiple 2D contour plots in the same window.
Plots can overlay each other, such as line contours
of electron concentration over color contours of doping concentration,
or they can be spaced apart by scaling the x and y coordinates.

To use this feature, select OVERLAY at the main menu. You will be put into
a subsystem which has these features:
\begin{itemize}
\item 
Add - Add a contour plot to the plot list. You will be prompted for
the quantity to plot, if the dataset contains multiple quantities.
You can also specify plot attributes such as contour values,
grid, junctions, etc. You can also apply scaling or expressions
to the x and y coordinates and the data itself.
A total of forty separate contour plots can be plotted at once.
\item 
Clear - Delete all data from the plot list. Useful for ``starting over''.
\item 
Delete - Delete a dataset from the plot list.
\item 
List - List all data to be plotted.
\item 
Modify - Modify various aspects of a dataset, such as contour values,
grid, junctions, etc. You can also apply scaling or expressions
to the x and y coordinates and the data itself.

You can also select whether a dataset
will be included in the plot. This is useful if you wish to store
a number of data items at one time, but selectively plot the entries.
\item 
Plot - Plot all the data as an contour graph. The plot menu allows the
user to set certain global plot attributes, such as applying a global set of
contours to be used with all datasets, and setting the dataset that
will be used for the sample function and also for plotting the contour
map legend at the side of the plot. The other functions available
for contour plots (e.g. zoom, unzoom, sample, save) are available
for overlay plots.
\item 
Read - Read a new data file.
\item 
Show - List information about a dataset
\item 
Exit, quit - Return to main menu.
\end{itemize}
%
\subsection{The FIND function}
The FIND function will search along a 1D cut line in the
device and print out where a simulation quantity reaches a certain
value. For example, you can use FIND to determine where the
lateral electric field is zero along the surface of the MOSFET
(Y=0).
%
\subsection{The INTEGRATE function}
The INTEGRATE function will integrate a quantity in an arbitrary
rectangular region in the device, or along a 1D cut line in the
X, Y or Z direction.
INTEGRATE prompts for the region to integrate, and will
check to make sure the region is inside the device.
INTEGRATE prints out certain landmarks
in the device, such as
the source and drain contact positions, and the gate position,
for the user's convenience in specifing the region.
Note that the integration area is rounded to the nearest simulation
mesh line, so integration over exact regions is not
possible in general. In most cases, there are sufficient mesh lines
to resolve the use specified integration region.
As a check, POSTMINI will print out the actual integration region
for the user to check.
Also note that the resulting integrated value is given per centimeter (cm)
device width (or length/depth, if 3D data is being integrated).

Integration over a line can be thought of as integrating over a plane
that is inserted perpendicularly to the simulated device (in the z,
or width direction, for example).
When performing a line integration of a vector
quantity, such as current density or electric field, the
vector component perpendicular to the cut line is usually chosen.
For example, if the cut line is in the vertical (Y) direction,
the integral of the x component of the current density gives the
amount of current flowing though across that line.
One should be cautious when integrating the y component of the electric
field at the oxide interface since field is discontinuous at that
point.
POSTMINI computes the electric field at the
semiconductor side of the interface and uses the result at that point.

POSTMINI also allows you to perform a 1D integration of any 1D data
that has been loaded, e.g. from an ASCII file, SUPREM3, etc.

Note well: integrating over an area with the same X or Y coordinate
is {\em not} the same as integrating over a line. Quantities integrated
over a region are weighted by area ($\rm cm^2$),
while those integrated over a line
are weighted by length (cm). POSTMINI prints the units of the integrated
quantity to remind the user.

Note well: the integration method does not take nonplanar boundaries
correctly into account (uses entire area weight, rather than area in
just silicon). Use caution when integrating near nonplanar features.

Example 1: Integrate the avalanche generation over the entire device.
Multiply this number by the electronic charge q to get the
bulk current per cm of device width.
Note: this number can be different from what MINIMOS
prints, especially when the bulk current is very small compared to
the drain current.

Example 2: Integrate the X component of the minority current in a
vertical direction in the middle of the channel. This gives the
drain current per cm width of the device. Note, if MODEL=AVAL or HOT,
there may be a slight difference between this current and the drain current
printed by MINIMOS, due to additional current generated by
impact ionization. By varing the length of the integration line,
one can determine the amount of current that passes a certain depth.
%
\subsection{The LINE function}
Using the LINE function, you can print simulation internal quantities
along any vertical or horizontal line.
The first lines of the file are a header which lists the
quantity and cut line selected. This header is commented out using the CURV
program convention, so these files can be directly read by CURV.
Following the header, the data is printed out in two
columns: the coordinate (in microns) and the quantity at that coordinate.

When you print data into a file, POSTMINI creates a file
in your current directory, using the following algorithm to
generate the file name:
\begin{enumerate}
\item The stem of the binary file name is the first part of the print
file. Example: binary file is GEN505000.BIN; stem is GEN505000.
%
\item The coordinate of the cut is appended
to the file name in the format {\tt \_nnnnC}, where {\tt nnnn} is the
absolute value of the
cut coordinate value in 1000'ths of microns, and C is the
cut direction (X or Y). Examples: cut at X = 1.25 microns $\rightarrow$
{\tt \_1250X}; cut at Y = $-0.050$ microns $\rightarrow$ {\tt \_0050Y}.
%
\item The file type is a mnemonic code which depends on the quantity
selected. See section~\ref{sec:startup}dix B for the list of extensions and their meaning.
\end{enumerate}
%
\subsection{The MINMAX function}
The MINMAX function allows you to locate the minimum and
maximum of a quantity in the simulation.
Note that it is possible that there will be several places in the
device which have the same minimum or maximum value.
POSTMINI will report the first one it finds as it scans the device.
You can limit the seach to a portion of the device;
this is useful if you wish to limit seaching to the semiconductor
region (e.g. $y \ge 0$ in a planar MOSFET).
%
\subsection{The PRINT function}
Using the PRINT function, you can print simulation internal quantities
over the entire device to a file.
Output consists of a neatly printed array of data
values, with corresponding x and y coordinates.

When you print data into a file, POSTMINI creates a file
in your current directory, using the following algorithm to
generate the file name:
\begin{enumerate}
\item The stem of the binary file name is the first part of the print
file. Example: binary file is GEN505000.BIN; stem is GEN505000.
%
\item The file type is a mnemonic code which depends on the quantity
selected. See section~\ref{sec:startup} for the list of extensions and their meaning.
\end{enumerate}
%
\subsection{Changing POSTMINI defaults}
POSTMINI allows you to change a number of default plot attributes.
Use the {\tt default} function to modify them.