A lumped-circuit nonquasi-static (NQS) model, that is applicable for both large-signal transient simulations and a small-signal ac analysis, is developed in this paper. An improved physical equivalent circuit, capturing NQS effects in the millimeter waveband, is derived using a transmission line model, by incorporating the high-frequency longitudinal gate electrode and a channel distributed RC network. The proposed model is implemented in a BSIM-BULK MOSFET model and validated with dc and RF data, obtained from technology computer-aided design device simulations and experimental data. The proposed model is in very good agreement with the data up to ${50}{f}_{t}$ . The transient currents, for a gate-voltage switching rate of ${5}\times {10}^{{10}}$ V/s, show excellent match with the data. The dc, transient, and ac simulations using the proposed model are much faster than a 10-segmented MOSFET model. This shows that the proposed model is better than other computationally complex compact models, for most RF applications.

Accurate and Computationally Efficient Modeling of Nonquasi Static Effects in MOSFETs for Millimeter-Wave Applications

In this work, we present the recent and upcoming enhancements of the industry standard BSIM-BULK (formerly BSIM6) model. BSIM-BULK is the latest body referenced compact model for bulk MOSFETs having a unified core, which is developed by the BSIM group for accurate design of analog and RF circuits. The model satisfies the symmetry test for DC and AC, correctly predicts harmonic slope, and exhibits accurate results for RF and analog simulations. In order to further improve the model accuracy for transconductance $(g_{m})$ and output conductance $(g_{ds})$, an analytical model for bulk charge effect, in both current and capacitance, is implemented. Several other advanced models are added to capture real device physics. These include: parasitic current at the shallow trench isolation edges; leakage current components in zero threshold voltage native devices; new model for NQS to capture the NQS effects up to the millimeter wave regime; self heating effect; and heavily halo implanted MOSFET’s anomalous g m , flicker noise and I DS mismatch. All these enhancements have been implemented to high standards of computational efficiency and robustness.

BSIM-BULK: Accurate Compact Model for Analog and RF Circuit Design

Measurement and scalable modelcard development methodology for 180 nm Bulk MOSFET technology using BSIM-BULK compact model is presented in this paper. On-wafer device characterization is performed to extract the global parameter set. These devices are fabricated at Semi-Conductor Laboratory (SCL) Chandigarh, India. With the extracted parameter set, BSIM-BULK model accurately predicts the device behavior for entire range of temperature and device dimensions.

Characterization and Global Parameter Extraction of bulk MOSFETs using BSIM-BULK Model

The charge based compact model for Drain-Extended MOS (DEMOS) transistor is presented in this work. Proposed model accurately predicts the special effects of quasi-saturation, present in high voltage MOSFETs. Modeling methodology used in this paper includes the drift resistance model based on intrinsic drain current, and low voltage BSIM-BULK model. Developed model along with the BSIM-BULK compact model can be used for the modeling of low voltage bulk MOSFETs to DEMOS transistors. Proposed model results are validated with Technology Computer-Aided Design (TCAD) DEMOS data. The model is accurately capturing the impact of drift region on DC I-V characteristics and their derivatives.

Compact Modeling of Drain-Extended MOS Transistor Using BSIM-BULK Model

An accurate physics-based lumped-circuit model, representing the nonquasi-static effect and the distributed polygate electrode resistance in bulk MOSFET is proposed. In our approach, an improved physical equivalent circuit capturing NQS effect is developed by using pole-zero compensation technique. The new model takes into account the inherent delay in the response of channel charges to the applied voltage. The proposed model is implemented in BSIM6 MOSFET model, and it is validated with Y-parameter data obtained from technology computer-aided design device simulations. The proposed model is in very good agreement with the device data up to 50/t, which ensures that it is suitable for most RF applications over any other computationally complex compact models.

Noor Mohamed

Papers

Compact modeling of nonquasi-static effect in bulk MOSFETs for RF circuit design in sub-THz regime