Hints, Tips and Solutions

Q. How many device geometries can be measured with BSIM3 extraction routine and used for optimization in ALL_DC routines?

A: The BSIM3 parameter extraction routine can be used to measure up to 36 different geometries. After the initial parameter extraction is completed the data can be transferred to ALL_DC routines for Local or Global optimization. The data transfer from the BSIM3 to ALL_DC routines is done automatically during the loading of the log file.

The setup structures of the BSIM3 and ALL_DC routines are different. During the internal data conversion, ALL_DC routines read the BSIM3 data curves in pairs (for low and high bias). Therefore each device has two entries in the model strategy screen for ALL_DC routines. Each pair of data curves uses single ALL_DC routine setup. For optimization purposes the number of geometries are limited by the number of setups ALL_DC routine has. Recently the number of setups in ALL_DC routines is increased to 36! This enhancement allows users to transfer data for up to 18 devices between the BSIM3 and ALL_DC routines without loosing any data for optimization.

New Capabilities in the "Library Generation Screen"

The library generation screen is modified to accommodate the UTMOST users requirements for more sophisticated utilization of the model libraries. (Figure 1.)

The number of characters for the library and model names are increased to 50.This will allow users to put more information into the library and model names.

Figure 1. New library generation screen.

The Library/Model attributes are carried into Library Title Screen (Figure2.) This screen will allow users to store and view more information about the SPICE library models. In order to open the Library title screen press the "Spice Summary" button in the Library Generation Screen. This will open the "Library Summary Screen". Highlight a model and Press the "Attributes" button. The Library title screen will be opened showing the model's attributes.

Figure 2. Llibrary title screen.

The other major improvement in the Library Generation Screen is the Expand Model Table button. When enabled, this button allows users to automatically append new parameter names to the existing parameter table. In order to copy the parameters into the UTMOST's parameter screen the DISPLAY---> UTMOST button should be pressed. However if there are parameters in the display screen which do not exist in the Parameter Screen, UTMOST will issue a warning message indicating "Mismatching is found" between the two tables. To overcome this problem the user has to go back to the parameter screen and add the new parameter names to the parameter table and try to copy again. This process has to be repeated for each parameter name which does not exist in the parameter table. Using the new Expand Model Table button this time consuming process can be totally avoided.