Question

At room temperature a possible value for the mobility of electrons in the inversion layer of a silicon n-channel MOSFET is:
1. 450 cm²/V-s
2. 1350 cm²/V-s
3. 1800cm²/V-s
4. 3600 cm²/V-s

Answer 1

Correct Answer - Option 2 : 1350 cm²/V-s

 

	Ge	Si
Electron Mobility	3800 cm2 /V-sec	1300 cm2 /V-sec
Hole Mobility	1800	500 cm2 /V-sec

 

Difference between P-channel MOSFET  and N-channel MOSFET MOSFET

•  P-channel is much easier and cheaper to produce compared to N-channel MOSFET device.
• The N-channel MOSFET has a high packing density. This makes it faster for switching applications due to smaller junction areas and low inherent capacitances.
•  N-channel MOSFET is smaller for the same complexity compares to P-channel MOSFET.
•  Drain resistance of P-channel MOSFET is 3 times higher than identical N-channel MOSFET devices.
•  N-channel MOSFET has a high false turn-on possibility compare to a P-channel device. This is due to positively charged contaminants.
•  Forgiven drain current rating, P-channel MOSFET occupies a larger area compare to N-channel MOSFET. This is due to the fact that electron mobility is 2.5 times than mobility of the hole.