Course

Unit 1:

Basics of Semiconductor – Intrinsic and Extrinsic Semiconductors, Equilibrium in absence and presence of Electric Field, Non-Equilibrium and Quasi-Fermi Levels, Charge Density. Electric Field, Potential, Poisson’s Equation, Transit Time, Drift and Diffusion current, Contact Potentials, The pn Junction. Overview of the MOS Transistor – Structure, Operation and Characteristics of MOS Transistor. The Two-Terminal MOS Structures – Flatband Voltage, Potential Balance and Charge Balance, Effect of Gate-Body Voltage on Surface Condition, Accumulation and Depletion, Inversion, Small-Signal Capacitance.

Unit 2:

The Three-Terminal MOS Structure – Contacting the Inversion Layer, The Body Effect, Regions of Inversion, A “VCB Control” Point of View, Uses for Three-Terminal MOS Structures.
The Four-Terminal MOS Transistor – Transistor Regions of Operation, Complete All-Region Model, Simplified All-Region Models, Models Based on Quasi-Fermi Potentials, Regions of Inversion in Terms of Terminal Voltages, Strong Inversion, Weak Inversion, Moderate-Inversion and Single-Piece Models, Source-Referenced vs. Body-Referenced Modeling, Effective Mobility, Effect of Extrinsic Source and Drain Series Resistances, Temperature Effects, Breakdown, The p-Channel MOS Transistor, Enhancement-Mode and Depletion-Mode Transistors, Model Parameter Values, Model Accuracy, and Model Comparison.

Unit 3:

Small-Dimension Effects – Carrier Velocity Saturation, Channel Length Modulation, Charge Sharing, Drain-Induced Barrier Lowering, Punchthrough, Combining Several Small-Dimension Effects into One Model, Hot Carrier Effects and Impact Ionization, Velocity Overshoot and Ballistic Operation, Polysilicon Depletion, Quantum Mechanical Effects, DC Gate Current, Junction Leakage, Band-to-Band Tunneling and GIDL, Leakage Currents—Particular Cases, The Quest for Ever-Smaller Devices.

Large-Signal Modeling of MOS Transistor – Quasi-Static Operation, Terminal Currents in Quasi-Static Operation, Evaluation of Intrinsic Charges in Quasi-Static Operation, Transit Time under DC Conditions, Limitations of the Quasi-Static Model, Non-Quasi-Static Modeling, Extrinsic Parasitics.

Overview of Modern Semiconductor Devices – SOI MOSFETs, Multi-gate Gate FETs like -Double Gate, FinFET, Gate All Around FETs (GAA-FETs).

• Understand semiconductor fundamentals, pn junctions, and MOS structure behavior.
• Analyze two- and three-terminal MOS devices, focusing on inversion and capacitance.
• Model four-terminal MOS transistors across operating regions with practical effects.
• Study short-channel effects, develop large-signal and non-quasi-static models, and gain an overview of modern semiconductor devices.

At the end of the course, the student should be able to

• CO1: Explain the physical behavior of intrinsic and extrinsic semiconductors, pn junctions, and MOS   structures under various biasing conditions.
• CO2: Analyze the characteristics of two- and three-terminal MOS devices and interpret the effects of gate voltage on device behavior.
• CO3: Model four-terminal MOS transistors considering different regions of operation, mobility variations, and temperature effects.
• CO4: Evaluate short-channel effects and develop models for scaled MOS devices, with an overview of advanced structures including SOI, Double Gate, FinFET, and GAA-FETs.

Skills Acquired: Ability to model and analyze semiconductor devices using physical principles and apply advanced MOSFET models for modern nano-scale device design and simulation.

CO-PO Mapping:

1. Tsividis and C. McAndrew, Operation and Modeling of the MOS Transistor, Oxford University Press, 2011.
2. Donald Neamen, Dhrubes Biswas, Semiconductor Physics and Devices, McGraw Hill, 2017.
3. Jerry Fossum and Vishal Trivedi, “Fundamentals of Ultra thin body MOSFETs and FinFETs”, Cambridge University Press, 2013.
4. Jean-Pierre Colinge “FinFETs and other Multi Gate Transistors”, Springer (2008).
5. Samar K. Saha, “Compact Models for Integrated Circuit Design – Conventional Transistors and Beyond”, CRC Press (Taylor & Francis), 2016.