B 0800ECT201122006 Pages: 3

Reg No.: Name:
APJ ABDUL KALAM TECHNOLOGICAL UNIVERSITY
Third Semester B.Tech Degree Examination December 2020 (2019 Scheme)

Course Code: ECT201
Course Name: SOLID STATE DEVICES

Max. Marks: 100 Duration: 3 Hours
PARTA
Answer all questions. Each question carries 3 marks Marks

1 With suitable examples, distinguish between elemental and compound (3)
semiconductors. Give their applications.

2 Draw the energy band diagrams under equilibrium for the following (3)
semiconductors. i) intrinsic ii) n type ili) p type
Write down the current equations in a semiconductor. (3)

4 What is the significance of quasi fermi level? If there is gradient in quasi fermi (3)
level, what does it indicates?

5 Draw the V-I characteristics of a 0 N junction diode & mark the regions of (3)
operation. Write down the ideal diode equation.

6 18४ the structure of a PNP transistor. Clearly Indicate the current components (3)
on the figure.

7 210 the transfer characteristics of an n-channel MOSFET. Give the current (3)
equation.

8 An nMOS transistor has W/L= 4/2, gate oxide thickness 0 A’, Mobility of (3)
electrons 180 cm?/Vsec. The threshold voltage is 0.4 V, relative permittivity of
gate oxide €,, 53.9. Calculate the drain current when Vgs = 1.5 V, Vds = 1.8 ५.

9 What is channel length modulation in MOSFETs? How does it affect the output (3)
characteristics of the MOSFET?

10 Explain the principle of operation and advantage of FinFET. (3)

PART ‏تا‎
‎Answer any one full question from each module. Each question carries 14 marks
Module 1

11 a) Derive the equation for hole concentration in a semiconductor under thermal

equilibrium in terms of 7}, E;and E;.

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