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HSPICE LEVEL 6 MOSFET Model
The general form of the Ids equation for the HSPICE LEVEL 6 MOSFET model is similar to the UCB MOS LEVEL 2 model. However, small geometry effects such as mobility reduction and channel length modulation are modeled differently. Also, the LEVEL 6 model can be used for modeling MOS transistors with ion-implanted channels due to its multi-level GAMMA capability.
The HSPICE MOS LEVEL 6 model is based on the ASPEC, MSINC, and ISPICE MOSFET model equations and has been enhanced by Meta-Software. Different versions of the model are invoked with the switch parameter UPDATE. There are more than 5 other switch parameters that are used for selecting different model equations. Refer to the HSPICE User's Manual [2] for more information on this model.
The IC-CAP LEVEL 6 model parameter extraction routines and configuration file are described in this section. Three extraction functions for this model are included in the IC-CAP function library. The configuration file, hnmos6.mdl supports a limited number and combination of parameters in the LEVEL 6 model. However, different parameter combinations can be supported by modifying the included optimization strategy. This configuration file can also be used for the HSPICE MOS LEVEL 7 model, provided that the PHI parameter is set to PHI/2 following the extraction.
Note
Set the SIMULATOR variable to your version of HSPICE after loading the hnmos6.mdl configuration file into IC-CAP. Refer to Chapter 6, "Simulating," in the IC-CAP User's Guide for additional details on using HSPICE.
Model Parameters
The parameters used in the hnmos6.mdl example file are listed in the following table. Six switch parameters are selected in the supplied configuration. The fixed parameter values are based on typical MOSFETs; they may need to be altered for certain devices.
An important feature of the HSPICE LEVEL 6 model is its multi-level Gamma capability. IC-CAP extraction routines support both single- and multi-level Gamma parameters extractions. If VBO is set to 0 before the Large IdVg extraction, only GAMMA is extracted. Otherwise, GAMMA, LGAMMA, and VBO are extracted. Optimization is necessary with the LEVEL 6 model for optimum agreement between measured and simulated data.
The IC-CAP Setup attributes for the LEVEL 6 model are listed in Table 80.
Measurement
The measurement setups are identical to the UCB MOS LEVEL 2 and LEVEL 3 model example files. However, to obtain accurate GAMMA and LGAMMA parameters for ion-implanted devices, the measured data must clearly express the body effects. Therefore, the bulk voltage should be set broadly on the Large IdVg measurement. The following sequence for DC measurements is recommended:
| 1 | Large IdVg |
| 2 | Narrow IdVg |
| 3 | Short IdVg |
| 4 | Short IdVd |
Extraction and Optimization
All DC parameters are extracted and optimized with the DCExtraction macro. Alternately, extractions and optimizations can be performed interactively as described for the LEVEL 2 and LEVEL 3 MOSFET models. There is no extraction routine in the short IdVd setup for saturation region parameters. Instead, the parameters KU, MAL, MBL, and LAMBDA must be optimized. For certain devices it may be necessary to alter the optimization setup and default parameter values for accurate results.