UNIX
Machines and the
Silvaco
Device Simulations Helpful Hints
Logon: Activate your UNIX accountBe sure you have an active UNIX account. If you do not, go to the ECC help desk and let them know you want to activate your UNIX account. After that (it takes about 40 minutes) "test" your account by logging on to a UNIX machine. A simple way to do this is to use Telnet (your ECE 1331 course was good for something!) or else use QVT Term if you have it installed. You can login to any of the UNIX machines; a convenient one is V880.egr.uh.edu. (This is a pretty fast, 8-microprocessor/32 GB machine built by Sun Microsystems.)
Getting to a UNIX machine
To use Silvaco from a Windows machine, you need to run the emulator "X-Win32" . This is available on the ECC machines, which is where we suggest you do this.
After running X-Win32, an icon will appear in your tray (there are no " windows" here). You will need to set up a session by right-clicking on the X-Win32 icon and selecting "X-Config". Then‚ÄöSelect My Sessions and click on Manual under New Session Choose a session name (your choice).
For XDMCP Mode, you can do one of two things:
Choose Broadcast. Then Save and Launch. You should then be given a set of UNIX machines to choose to connect to. Pick any one you like.
Choose Query and for Host specify "V880.egr.uh.edu". Then Save and Launch. You should be connected to the V880 host.
Login to your UNIX account.
Basic UNIX commands
In the SOLARIS windows environment: to get a Terminal from which you can enter commands, click on the icon along the bottom row labeled "cpu disk" and choose "This Host".
ls list files in the current directory
ls -a list files in the current directory, including "hidden" files (which begin with ".")
pwd tell me the present working directory
cd change directory (followed by directory name)
cd .. move one directory up in the path
rm delete (remove, followed by filename to be deleted)
Getting to SILVACO: The .login File
Your "login" file runs every time you log in, and sets up things you need to run your programs. This is a "hidden" file; to view it, you need to be in your home directory, and then execute the command ls -a.
To do the SILVACO simulations, you should have the following line in your .login file. It doesn‚ÄöÃÑÃ¥t matter where it appears, but it is good practice to put it near the end of the file.
set path=($path /usr/local/SILVACO/bin)
To get these lines into the file, you must open .login in a text editor, of which there are several. To edit .login using the vi editor, for example, execute vi .login from your terminal. It would be a very good idea to back up your .login file first, however. Once you have added the set path line to your .login file, you save and quit by executing escape (esc) and then :q to quit without saving or :wq to write (save) the changes and then quit.
Once you have the path information in your .login file, you get to Silvaco by executing Deckbuild &. (The " &" allows other processes to run while Deckbuild is running; otherwise you have to quit Deckbuild to do anything else.)
The Simulation Software
Loading and Running Examples From Deckbuild, you can load example files by choosing Main Control/Examples. After selecting a topic, you will get the opportunity to pick several specific examples. Once you have the example you are looking for, choose Load example; the code will then be loaded into DeckBuild.
If you have run the same simulation before, there may be files in your directory that will be over-written when you load the example again. Choose "OK" when the warning is sounded. To run the example, just hit run in DeckBuild.
Finding Parameter Values Periodically in the code, VWF executes an Extract command, which finds the value of some particular variable, such as oxide thickness. These values are then printed in the output pane (lower pane in DeckBuild), along with a copy of the command itself. If you need to find these values, one way is to scroll through the text to find it. This is a pain, admittedly; just keep thinking about graduation. Another method is to use the plotting tools to " blow up" the region of interest and use the built-in scales to figure out the thickness.
Adjusting Plots From TonyPlot, you can adjust the plotting parameters by choosing Plot/Display. Choose the option you want from the icon box, and choose Apply. To adjust the colors of the display, choose Define/Contours/Colors. In that submenu, Rainbow 30 is a nice plotting option.
To get TonyPlot to give you a cut line, choose Tools/Cutline
Plotting Structure Files using TonyPlot It is possible to plot any structure file, including the history files, by the following method. (A structure file is any file that has the .str extension.) In the DeckBuild window, use the mouse to highlight the name of the file, for example .history.str, or mosexo01_0.str. Then, right click on the Tools menu, select Plots, and Plot Structure. This action will open TonyPlot and display the contents of the structure file.
Plotting Your Results To plot your results, what you do is to "print" to a file. Before doing so, you "define" a printer that has the properties you desire.
You define a new printer as follows. When you have a structure file displayed in TonyPlot, click on Print, and then click on Printers. In this dialogue box, you will define a printer and give it a name. Name it anything you choose. Now click Type, and choose pcx (256 colors). Now choose "Update". The result will be a new printer, whose name should appear on the list in the dialogue box.
Having defined a printer, go back to the Print menu, and choose Options. Choose File, and then choose your newly defined printer from the list at the left. Specify a file name (don‚ÄöÃÑÃ¥t forget the .pcx extension), and select "Print". You should now have a pcx file in your directory. You may now e-mail your file to yourself as an attachment, or else use ftp to retrieve it to your own computer, and print it.
Disk Quota VWF generates a large number of .history files, some of which are quite big. If you allow it to generate all it wants, it may exceed your disk quota. It turns out you have some control over this, as follows. Within Deckbuild, go to the Main Control menu, select Main Control (the first entry) and choose history files. This dialogue box will give you several options, including a "length" parameter, which refers to the number of history files VWF will generate before over-writing the earliest ones. Make this parameter a small number, like 5 or 6. In this way, the last few files generated will be available for you if you need them, but only five or six will be generated. This should handle the memory problem.
