BSIM4 Version 6.1

C-V Model

A new VgsteffCV definition is introduced in the C-V model to improve threshold fitting. Six new parameters have been added: CVCHARGEMOD, MINVCV, LMINVCV, WMINVCV, WMINVCV, PMINVCV, and VOFFCVL.

New Material Model

A new materials model (activated by setting MTRLMOD=1) has been introduced with the following features:

• • Predictive modeling of
    • Non-SiO2 insulator
    • Non-poly-Si gate New parameters
    • Non-silicon channel
  • Improved predictive models for GIDL/GISL leakage current, mobility degradation, and short channel effects
  • A model selector (MTRLMOD) is used to turn on/off all the new materials parameters and equations for backward compatibility.

New Materials Model Parameters

Model selector:

MTRLMOD : =1 activates the new-materials option and =0 (default) deactivates

For non-poly-silicon gate:

• PHIG : Gate work function
• EPSRGATE : Dielectric constant of gate relative to vacuum ( = 0 deactivates poly depletion)

For non-SiO2 gate-dielectric:

• EOT : Equivalent SiO2 thickness
• VDDEOT : Gate voltage at which EOT is measured

For non-silicon channel material:

• EASUB : Electron affinity of substrate
• EPSRSUB : Dielectric constant of substrate relative to vacuum
• NI0SUB : Intrinsic carrier concentration at T=300.15K
• BG0SUB : Band-gap of substrate at T=0K
• TBGASUB : First parameter of band-gap change due to temperature
• TBGBSUB : Second parameter of band-gap change due to temperature
• ADOS : Density of states parameter to control charge centroid
• BDOS : Density of states parameter to control charge centroid

Non-Silicon Channel Material

Defines the temperature-dependent intrinsic carrier concentrations and the band gap with the new non-silicon parameters for MTRLMOD = 1.

(-261)

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Introduces two new parameters for charge centroid for non-silicon channel materials in both I-V and C-V models.

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Non-SiO2 Dielectric Material

For MTRLMOD = 1, use EOT (defined as the electrical oxide thickness at V_gs = VDDEOT) to calculate oxide thickness at flatband voltage.

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Non-poly-Si gate Material

Poly depletion is calculated using the following equation:

(-267)

where

(-268)

Setting EPSRGATE = 0 turns the poly depletion model off.

Improved Mobility Model

The new equations for the improved mobility model are given in the coming sections.

Improved GIDL/GISL Model

For MTRLMOD=1, the flat band voltage at source/drain is given in the coming sections. New equations for the GIDL and GISL model are also given.

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