**Academic year:**

Autumn 2018

**Course Instructor:**

Prof. Souvik Mahapatra

**Motivation for this course (a.k.a why should I do this course):**

EE207 is a compulsory 3rd semester core course of the Electrical Engineering department. For a electrical undergraduate, this course is like a continuation to the semiconductor physics that he/she studies in EE112. In EE112 he/she would have learnt many equations and phenomenon that take place in various semiconductor devices. This course is an attempt to understand the physics behind these equations and phenomenon.

If you are genuinely interested in the inner workings of semiconductor devices, this course is for you. Semiconductor devices are everywhere around us. Understanding the physics behind them made us progress from an era where a hard disk of 2.52GB weighted around 250Kg and costed around $100,000 to an era where one can store 4TB in a hard disk that weighs 250g and costs around $150.

Finally, this course acts as a prerequisite for many courses in the field of microelectronics.

**Prerequisites:**

This course was taught to us from scratch. It doesn’t have any official prerequisites. Knowledge of the basic semiconductor physics that one learns in JEE or in EE112 might be helpful.

**Course Content:**

Basics of semiconductor physics Energy Band diagrams and effective mass and the concept of holes, Fermi distribution The concepts of Generation and Recombination (SRH process) The carrier drift and the carrier diffusion equations, The continuity equations The PN junction and the concept of minority carrier Injection Special diodes: Zener diodes, Tunnel diodes, Photodiodes….etc Switching transients of the PN junction Physics behind the BJT and the Ebers-moll model of BJT MOS Capacitor and its CV characteristics, Band diagrams Impact of non-idealities on MOSCAP characteristics – Effect of traps, fixed charges and tunnelling Physics behind the working of MOSFET – Band diagrams and equations Non-idealities in MOSFET – Channel length modulation, DIBL, velocity saturation and some reliability issues in MOSFETs

**Feedback on the Lectures:**

The difficulty of understanding the lectures in this course goes on increasing exponentially as the semester passes on, when one starts either missing classes or sleeping through them. So, it’s very critical that one attends each and every class and pays attention to what the professor is saying. This course involves a lot of scary looking equations. The slides given by the professor were very useful while preparing for the exams provided that one has paid attention in class. This is because, though the slides have proper derivations and explanations of the equations taught in class, the theory behind it can only be acquired by going to the class

**Feedback on assignment, quizzes and exams:**

The breakup of the weightage for assignments, quizzes and exams is as follows:

Quiz-1: 15%

Mid-sem: 25%

Quiz-2: 15%

Assignments: 10%

End-sem: 35%

**Assignments:**

The professor gave us a MATLAB assignment where he asked us to simulate the kronig-penney model. This was a really tough one, especially because, most of the students didn’t know MATLAB. The course also involved regular written assignments, consisting of numericals. Many questions in the earlier quizzes and midsem were directly from the assignments, so be sure to solve them on your own.

**Quizzes and Exams:**

The quizzes and the exams were considered really tough with many people scoring low marks in the first quiz. As such the quiz and other exam questions themselves were not so hard, but people scored poorly since they found the course tough to understand. The prof allowed cheat sheets for most exams and every exam focused on a different aspect that the prof. considered important for us to learn. Some quizzes focussed highly on the student’s ability to apply suitable numerical techniques and the formulae, without making any error in the process whereas others focussed more on the student’s understanding of the I-V characteristics and band diagrams. Also, the midsem questions were exactly same as in one of the previous papers, so be sure to have a look at previous papers before the exams 🙂

**Difficulty:**

Overall the course was difficult especially for those who were not attending classes regularly

**Grading Statistics:**

The combined grading statistics(BTech + Dual) was pretty lenient with 19 getting AAs and 32 getting ABs and 35 people getting BBs out of a class of 142. (That’s more than half of the class with grade >= 8) But, I highly doubt that the BTech professor was lenient in grading.

**Reference Materials:**

The best reference material for this course is a book by an MIT professor, Robert Pierret:

Robert F. Pierret – Semiconductor Device Fundamentals

(The professor himself followed this, with some of the images in the slides exactly from this book)

**Additional References:**

B.G.Streetman, S.K.Banerjee – Solid State Electronic Devices Global Edition-Pearson Education Limited D. A. Neamen, Semiconductor Physics and Devices