Metal oxide semiconductor field effect transistor MOSFET

Homework assignment due Tuesday, March 31 You are to take this exam and re-answer the questions using a different color pencil or pen. You are to work alone but you may consult your notes, the textbook or the lectures. Each of the 25 problems will be graded as 0, 1 or 2 – you can earn 50 more points for your homework score. The goal for you is to learn the fundamentals and also improve the grade

Final oral and written reports You are to choose a topic of interest to you in the general area of materials and devices. PowerPoint presentation in class – approximately 7 minutes -- April 30 & May 5 Short written report (3 to 5 pages) due May 7 – save as “your name” and submit via e-mail. Grading will be based on topic, impact & English Feel free to communicate with me concerning ideas. Exam #2 – in class May 7

Julius Edgar Lilienfeld (1881-1963) was an Austrian-Hungarian physicist. He was born in Lemberg in Austria-Hungary Among other things, he invented the field effect transistor (in 1925) and the electrolytic capacitor in the 1920s. He filed several patents describing the construction and operation of transistors as well as many features of modern transistors. When Brattain, Bardeen and Shockley tried to get a patent on their device, most of their claims were rejected due to the Lilienfeld patents.

Depletion layer

Basic structure of the MOSFET

Basic idea of the MOSFET - -

Basic model of the MOSFET - Basic model of the MOSFET E

Characteristics of the MOSFET Biasing controls this voltage

Application of the MOSFET

MOS capacitor A o

MOS capacitor p type semiconductor voltage bias effects - - - - E + + + +

MOS capacitor p type semiconductor voltage bias effects –battery switched + + + + E + - + - + - + -

MOS capacitor p type semiconductor gate voltage VG = 0

MOS capacitor p type semiconductor -- gate voltage VG < 0 accumulation

MOS capacitor p type semiconductor gate voltage VT > VG > 0 depletion

MOS capacitor p type semiconductor gate voltage VG = VT “threshold” Deeper & wider depletion

MOS capacitor p type semiconductor gate voltage VG > VT Deeper & wider inversion

P type Inversion P type depletion Problem 6.1 Charge distributions are depicted in an MOS capacitor. 1) Is the semiconductor n or p type? 2) Does the bias make it an accumulation mode, depletion mode or an inversion mode? P type Inversion P type depletion

n type inversion P type accumulation Problem 6.1 Charge distributions are depicted in an MOS capacitor. 1) Is the semiconductor n or p type? 2) Does the bias make it an accumulation mode, depletion mode or an inversion mode? n type inversion P type accumulation

Simple three-dimensional unit cell