Harshit Agarwal

BSIM6: Analog and RF Compact Model for Bulk MOSFET

BSIM6 is the latest industry-standard bulk MOSFET model from the BSIM group developed specially for accurate analog and RF circuit designs. The popular real-device effects have been brought from BSIM4. The model shows excellent source-drain symmetry during both dc and small signal analysis, thus giving excellent results during analog and RF circuit simulations, e.g., harmonic balance simulation. The model is fully scalable with geometry, biases, and temperature. The model has a physical charge-based capacitance model including polydepletion and quantum-mechanical effect thereby giving accurate results in small signal and transient simulations. The BSIM6 model has been extensively validated with industry data from 40-nm technology node.

Recent enhancements in BSIM6 bulk MOSFET model

In this paper, we discuss the recent enhancements made in the BSIM6 bulk MOSFET model. BSIM6 is the latest compact model of bulk MOSFET from BSIM group which have body referenced charge based core. Junction capacitance model is improved over BSIM4 and is infinitely continuous around Vbs=Vbd=0V. Symmetry of the model is successfully validated by performing Gummel Symmetry Test (GST) in DC and symmetry test for capacitances in AC. Self heating model is also included in BSIM6 and test results are reported. Model capabilities are compared against an advanced 40nm CMOS technology and it is observed that simulated results are in excellent agreement with the measured data.

Unified Compact Model Covering Drift-Diffusion to Ballistic Carrier Transport

In this letter, we present a unified compact model, which accurately captures carrier transport from the drift-diffusion to ballistic regime. This is a single unified model, which accounts for carrier degeneracy effects in ballistic transport. The model is implemented into the industry standard compact models for FinFETs, fully depleted silicon-on-insulator (FDSOI) devices and bulk MOSFETs: 1) Berkeley Spice model for common multi-gate; 2) Berkeley Spice model for independent multi-gate; and 3) BSIM6. The model is validated with experimental data and TCAD simulations for FDSOI devices, FinFETs, and bulk MOSFETs.

Analytical Modeling and Experimental Validation of Threshold Voltage in BSIM6 MOSFET Model

In this paper, an analytical model of threshold voltage for bulk MOSFET is developed. The model is derived from the physical charge-based core of BSIM6 MOSFET model, taking into account short channel effects, and is intended to be used in commercial SPICE simulators for operating point information. The model is validated with measurement data from IBM 90-nm technology node using various popular threshold voltage extraction techniques, and good agreement is obtained.

BSIM-IMG: Compact model for RF-SOI MOSFETs

Emerging market of RFSOI applications has motivated us to come up with the robust compact model for RFSOI MOSFETs. In this work, we have validated the RF capabilities of BSIM-IMG model which is the latest industry standard compact model for independent double gate MOSFETs. Results are validated with the experimental S-parameter data measured. Model shows good agreement for different biases over wide frequency range from 100KHz-8.5GHz.

Modeling of Subsurface Leakage Current in Low

We present a phenomenological model for subsurface leakage current in MOSFETs biased in accumulation. The subsurface leakage current is mainly caused by source-drain coupling, leading to carriers surmounting the barrier between the source and the drain. The developed model successfully takes drain-to-source voltage (VDS), gate-to-source voltage (VGS), gate length (LG), substrate doping concentration (Nsub), and temperature (T) dependence into account. The presented analytical model is implemented into the BSIM6 bulk MOSFET model and is in good agreement with technology-CAD simulation data.

V_{\mathrm {TH}}

This work presents new compact models that capture advanced physical effects presented in industry FinFETs. The presented models are introduced into the industry standard compact model BSIM-CMG. The core model is updated with a new unified FinFET model, which calculates charges and currents of transistors with complex fin cross-sections. In addition, threshold voltage modulation from bulk-bias effects and bias dependent quantum mechanical confinement effects are incorporated into the new core model. Short channel effects, affecting threshold voltage and subhtreshold swing, are modeled with a new unified field penetration length, enabling accurate 14nm node FinFET modeling. The new proposed models further assure the BSIM-CMG models capabilities for circuit design using FinFET transistors for advanced technology nodes.

Short Channel MOSFET at Accumulation Bias

The channel in Fully Depleted Silicon On Insulator (FDSOI) transistors is completely isolated from the substrate via buried oxide (BOX) and from the sides by shallow trench isolations, which results in high thermal resistance (Rth). Further, Rth increases with reduction in channel length (Lg). In this paper, we have proposed a compact model for the geometry and temperature dependence of Rth in FDSOI transistors. The model is validated against experimental and Technology Computer Aided Design (TCAD) data. The proposed model is implemented in the independent multi-gate model (BSIM-IMG) for FDSOI transistors. Graphical abstractThe channel in Fully Depleted Silicon On Insulator (FDSOI) transistors is completely isolated from the substrate via buried oxide (BOX) and from the sides by shallow trench isolations, which results in high thermal resistance (Rth). Further, Rth increases with reduction in channel length (Lg). In this paper, we have proposed a compact model for the geometry and temperature dependence of Rth in FDSOI transistors. The model is validated against experimental and Technology Computer Aided Design (TCAD) data. We also validate the radio-frequency (RF) model with measured high frequency data. The proposed model is implemented in the independent multigate model (BSIM-IMG) for FDSOI transistors.Display Omitted HighlightsGeometrical scaling of thermal resistance in FDSOI transistor has been analyzed.A new behavioral model for thermal resistance scaling has been proposed.The model is validated against experimental and Technology Computer Aided Design (TCAD) data.The BSIM-IMG model is validated on the measured RF characteristics for wide bias and frequency ranges.

BSIM-CMG: Standard FinFET compact model for advanced circuit design

An improved analytical model for flicker noise (1/f noise) in MOSFETs is presented. Current models do not capture the effect of high-trap density in the halo regions of the devices, which leads to significantly different bias dependence of flicker noise across device geometry. The proposed model is the first compact model implementation capturing such effect and show distinct improvements over other existing noise models. The model is compatible with BSIM6, the latest industry standard model for bulk MOSFET, and is validated with measurements from 45-nm low-power CMOS technology node.

Thermal resistance modeling in FDSOI transistors with industry standard model BSIM-IMG

In this paper, we have reported the improved surface potential calculation in the BSIM-IMG model for FDSOI MOSFETs. Model validation is done with the experimental data provided by Low-power Electronics Association and Project (LEAP). The model shows accurate behavior for C-V and I-V characteristics while keeping smooth behavior for their higher order derivatives. Model has smooth transition from weak inversion to strong inversion and satisfies DC and AC symmetry tests.