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Advanced concepts including generation-recombination, hot electron effects, and breakdown mechanisms; essential features of small ac characteristics, switching and transient behavior of p-n junctions, and bipolar and MOS transistors; fundamental issues for device modeling; perspective and limitations of Si-devices. Course Information: 3 undergraduate hours. 3 graduate hours. Prerequisite: ECE 340.

Microelectronics and Photonics

Advanced concepts in semiconductor electronics with real device structures and limitations of ideal models for device operation. Fundamental device equations, generation-recombination, hot electron effects, performance limitations. Numerical device simulation of PN junction and MOS field effect transistor.

This course is designed to provide undergraduate students with a wide background and the ability to deal with advanced concepts in semiconductor electronic devices.

• Review of semiconductor electronics, band model for solids, free carriers statistics, transport in semiconductors, drift mobility, hot electrons, diffusion
• Fundamental equations for semiconductor devices: current equations, Poisson equation, study cases, continuity equations
• P-N junctions: potential barriers, quasi-neutrality, static properties, reverse biased junctions, avalanche and Zener breakdowns
• Current in PN Junctions: Shockley-Hall-Read Model, I-V characteristics, charge storage and transients, numerical simulation of PN Junctions
• Bipolar transistors: basic properties, transistor action-Gummel number, amplifications, switching
• Bipolar transistors, limitations and models: Early effect, low and high emitter biases, base resistance, base transit time-charge control model and transients
• MOS systems: energy band diagram, accumulations, depletion, inversion, capacitance, MOS electronics, threshold voltage, oxide and surface charges
• MOSFET: basic theories and models, MOSFET parameters, Body effects, transconductance, speed of response, channel-length modulation, MOSFET design, control of the threshold voltage, CMOS, technological evolution
• MOSFET, Limitations: sub-threshold current velocity saturation, surface mobility, short and narrow channel effects, hot carriers MOSFET breakdown, MOSFET scaling, numerical simulation of MOSFET characteristics

This course is designed to provide undergraduate students with a wide background and the ability to deal with advanced concepts in semiconductor electronic devices.

Topics:

• Review of semiconductor electronics, band model for solids, free carriers statistics, transport in semiconductors, drift mobility, hot electrons, diffusion
• Fundamental equations for semiconductor devices: current equations, Poisson equation, study cases, continuity equations
• P-N junctions: potential barriers, quasi-neutrality, static properties, reverse biased junctions, avalanche and Zener breakdowns
• Current in PN Junctions: Shockley-Hall-Read Model, I-V characteristics, charge storage and transients, numerical simulation of PN Junctions
• Bipolar transistors: basic properties, transistor action-Gummel number, amplifications, switching
• Bipolar transistors, limitations and models: Early effect, low and high emitter biases, base resistance, base transit time-charge control model and transients
• MOS systems: energy band diagram, accumulations, depletion, inversion, capacitance, MOS electronics, threshold voltage, oxide and surface charges
• MOSFET: basic theories and models, MOSFET parameters, Body effects, transconductance, speed of response, channel-length modulation, MOSFET design, control of the threshold voltage, CMOS, technological evolution
• MOSFET, Limitations: sub-threshold current velocity saturation, surface mobility, short and narrow channel effects, hot carriers MOSFET breakdown, MOSFET scaling, numerical simulation of MOSFET characteristics

Use of TCAD for device simulation as HW

HW every week

N/A

N/A

• Concepts of modern physics
• Calculus and applications of differential equations
• Elements of device electronics

R. S. Muller and T. I. Kamins, Device Electronics for Integrated Circuits, 3rd ed., Wiley, New York.

Engineering Science: 2 credits or 67%
Engineering Design 33%

This course is a technical elective for electrical engineering majors, and is recommended for students pursuing Graduate Study in Physical Electronics and Microelectronics. The course deals with advanced physical and technological concepts in Solid State Electronics Devices and prepares electrical engineering majors for taking follow-on courses in these areas.

A. By the time of the Mid Term Exam (after 20 lectures + review), the students should be able to do the following:

1. Explain advanced physical concepts in Semiconductor Electronics such as carrier and impurity statistics, and hot carriers transport effects. (1)

2. Set-up an electronic model for the charge distribution at a semiconductor interface as a function of the interface conditions. (1,6)

3. Apply Poisson equation to find the electronic properties of a semiconductor homojunction, a metal-semiconductor junction and a insulator-semiconductor junction with interface charge. (1)

4. Explain the concepts of graded impurity distribution and potential barrier, and related approximations such as the depletion and quasi-neutrality approximations. (1)

5. Explain the concept of Debye length (intrinsic and extrinsic) (1)

6. Explain the concept of abrupt and graded doping. (1)

7. Compute the doping profile of an asymmetric P-N junction given Capacitance -Voltage characteristics. (1)

8. Explain the concept of breakdown voltage in relation with Avalanche and Zener breakdown. (1)

9. Explain the difference between donors/acceptors, traps and recombination centers. (1)

10. Apply the Shockley-Hall-Read model to determine the recombination rate of carriers in semiconductors. (1,6)

11. Explain the advanced concepts of Auger recombination and Surface recombination. (1)

12. Determine the carrier lifetime with the mechanisms defined in 10 and 11 above. (1,6)

13. Estimate and discuss the importance of space-charge region currents in a P-N junction. (1,6)

B. By the time of the Final Exam (42 lectures + Midterm exam + review), the student should be able to do all of the items listed under A plus the following:

14. Explain in detail the principle of BJT action and the difference between a prototype transistor and real transistors for intergrated circuits. (1)

15. Compute the Gummel number of a BJT. (1)

16. Explain the Early effect and its consequence for the BJT performances. (1)

17. Explain the effects of low and high emitter biases for the BJT performances. (1)

18. Explain the Kirk effect in BJT’s. (1)

19. Estimate the effects of base resistance and its consequence for the BJT performances. (1)

20. Estimate the base transit time in a BJT as a function of the base graded doping. (1)

21. Use the charge-control model to determine the switching characteristics of a BJT. (1)

22. Explain the concept of deep-depletion and its influence on the C-V curve of a MOS system. (1)

23. Derive the different surface regimes from the C-V curve of a MOS system.(1,6)

24. Determine the different components of the oxide charge and their influence on the flat-band voltage and the threshold voltage. (1,6)

25. Explain the difference between the charge control model and the variable-depletion charge model for the I-V characteristics of a MOSFET. (1)

26. Estimate theoretically the transit time of a MOSFET before saturation. (1,6)

27. Extract the threshold voltage of a MOSFET from experimental data. (1,6)

28. Determine the design rule for the threshold voltage of a MOSFET. (1,2)

29. Estimate the magnitude of the subthreshold current in a MOSFET. (1)

30. Discuss the causes for the channel velocity modulation in a MOSFET. (1)

31. Discuss the effects of hot carriers, short and small channel MOSFET’s on the performances of the devices. (1,2)

32. Discuss the breakdown mechanisms in MOSFET’s. (1)

33. Explain the scaling laws for smaller size MOSFET’s. (1,2)