Using CaMEL at Dartmouth

CaMEL consists of parameterized and nonparameterized cell libraries.

The nonparameterized cell library is a database of MEMS designs from a a variety of sources in the MEMS community. Some are complete devices, some are cells of structures you may find useful as building blocks. Information is also given on device yield. Your favorite structures can be added to this library using DBSubmit (but please clear them with the Chris Levey or Al Henning first). These designs come in fixed sizes, (though you can scale the entire cell in L-Edit, or by editing the CIF file).

The parameterized library (PME) includes generators which create customized layout for many common MEMS components that use a surface micromachined process technology such as the MUMPS process. The PME library is more flexible than the nonparameterized library because the user can specify parameters such as inner and outer radius, rotation angle. The generators support CIF and GDSII mask formats, as well as PostScript for printing.

At Dartmouth, you can access both libraries through programs running on germain, the same HP workstation that runs L-Edit.


Accessing the nonparameterized CaMEL MEMS library

  1. Use an xterm window from any northstar machine, or a DarTerminal window from a Macintosh to connect to germain and login under your northstar account. If you are using an xterm window, you would make the connection by typing:
    telnet germain.dartmouth.edu
    
  2. Add the camel directory to your PATH by appending the following to your .cshrc.local file:
    set path = ( $path /usr/camel/bin)
    
    Now either logout and back in, start a new shell, or type:
    source .cshrc.local
    
    You need complete this step only once; it will be automatic each successive time you login.

  3. Now you need only type the following whenever you want to access the unparameterized database:
    DBRead
    
    The DBRead program (perl script) is self explanatory. When you are done, it will send mail to MCNC with your request for a CIF file. You'll receive an email response shortly thereafter with the CIF file enclosed. Be sure that you run DBRead from your account, so the response is sent to you!

    DBRead keeps a list of current cells in /tmp/DOC. This list is killed once a week, and also whenever germain is rebooted. The next time DBRead is run, it automatically downloads a new list from MCNC (which makes it seem slow to start up). This means that the list of cells can be up to a week out of date. If you want to be sure you have the most recent list of cells (at the expense of startup speed in DBRead), you can delete the /tmp/DOC directory before running DBRead as follows:

    rm -rf /tmp/DOC
    DBRead
    
    (if you get errors in the rm, it may be that another user is running DBRead and accessing the files).

Accessing the parameterized CaMEL PME library

  1. Use an xterm window from any northstar machine, or a DarTerminal window from a Macintosh to connect to germain and login under your northstar account. If you are using an xterm window, you would make the connection by typing:
    telnet germain.dartmouth.edu
    

  2. If you haven't already done so, add the /usr/camel/bin to your path as above.
  3. Edit a file containing the desired pme commands. For example, following section 3.4.2, you could build a motor with a pme file which does the following: The pme file called mymotor.pme would look like this:
    PME p1, p2;
    p1=rsdm1(21.0,27.0,51.0,53.0,80.0,18.0,27.0,18.0,12.0,0.0,rsdma);
    p2=bearing1(14.0,10.0,27.0,jnla);
    instance(p1,'*',0.0,0.0,0.0);
    instance(p2,'*',0.0,0.0,0.0);
    
  4. Create a CIF file from your pme file (continuing the example above):
    cifpme  mymotor.pme >mymotor.cif
    
  5. If you want to use the file on Macintosh or PC, you will need to get it with an ftp program such as Fetch.
  6. To load your CIF file into L-Edit, you must first have a compatible technology file defined. The file mpmems.tdb from MCNC is almost a match, but the layer Conn is defined as FOO instead of MPT. You can edit this definition to match the camel definition: under the Setup menu, select CIF. Where you see the layer Conn, select FOO and type MPT. Click OK to dismiss the window. Now you can use the open command under the file menu to load your CIF file. Be sure to click the CIF button.

WARNINGS on using CaMEL with L-Edit

The CaMEL library will instance cells at 45 degrees and at odd angles. L-Edit doesn't know how to read such cells yet. Also, it generates curves as polygons which do not maintain Manhattan geometry. L-Edit will not generate layers from such polygons.

CaMEL User's Guide


Christopher.G.Levey@dartmouth.edu