What are the main constructional differences between a MOSFET and a BJT? What effect do they have on the current conduction mechanism of a MOSFET? 
by

1 Answer

0 like 0 dislike
A MOSFET like a BJT has alternating layers of p and n type semiconductors. However, unlike BJT the p type body region of a MOSFET does not have an external electrical connection. The gate terminal is insulated for the semiconductor by a thin layer of SiO2. The body itself is shorted with n+ type source by the source metallization. Thus minority carrier injection across the source-body interface is prevented. Conduction in a MOSFET occurs due to formation of a high density n type channel in the p type body region due to the electric field produced by the gate-source voltage. This n type channel connects n+ type source and drain regions. Current conduction takes place between the drain and the source through this channel due to flow of electrons only (majority carriers). Where as in a BJT, current conduction occurs due to minority carrier injection across the Base-Emitter junction. Thus a MOSFET is a voltage controlled majority carrier device while a BJT is a minority carrier bipolar device. 

Distributed under Creative Commons Attribution-ShareAlike - CC BY-SA.

Version 2 EE IIT, Kharagpur
by

Related questions

1 answer
0 answers
asked Mar 19, 2018 by Quiz | 22 views
1 answer
2 answers
0 answers
asked Mar 19, 2018 by Quiz | 20 views
0 answers
asked Mar 19, 2018 by Quiz | 21 views
1 answer
asked Mar 19, 2018 by Zeeshan | 272 views
0 answers
1 answer
asked Sep 6, 2018 by Someone | 13 views
0 answers
asked Mar 19, 2018 by Quiz | 21 views
0 answers
0 answers
asked Mar 19, 2018 by Quiz | 26 views
2 answers
asked Mar 19, 2018 by Quiz | 37 views
0 answers
2 answers
asked Nov 10, 2017 by Quiz | 152 views
1 answer
asked Sep 29, 2017 by Quiz | 286 views
1 answer
asked Sep 13, 2017 by Quiz | 60 views
1 answer
asked May 12, 2018 by Someone | 17 views
1 answer
asked May 12, 2018 by Someone | 14 views
1 answer
3 answers
asked Mar 19, 2018 by Someone | 53 views
0 answers
asked Mar 19, 2018 by Quiz | 29 views
4 answers
asked Mar 10, 2018 by Quiz | 219 views
1 answer
asked Jan 22, 2018 by Quiz | 32 views
1 answer
asked Dec 16, 2017 by Quiz | 16 views
1 answer
asked May 12, 2018 by Someone | 13 views
1 answer
asked Mar 19, 2018 by Someone | 21 views
1 answer
asked May 13, 2018 by Someone | 53 views
1 answer
asked May 12, 2018 by Someone | 14 views
0 answers
asked Mar 19, 2018 by Quiz | 23 views