1. The term 'Saturation' has a different
meaning in the I-V characteristics of MOSFET and BJT.
Explain the difference between BJT and MOSFET.
2. In MOSFET, carriers need to move from Source to Drain
via the inversion channel under certain Vgs and Vds conditions.
A "Pinched off" channel takes place at the
drain side. Now explain how the carriers move in the Pinched
off region of the channel (that is, the depleted portion of channel,
near the drain end) ? In other words, if the channel is pinched
off, then there are 'negligible' amounts of carriers there. How can
it conduct electric currnets ?
3. In a MOSFET, if one increases |Vds| in the saturation region, the Id will remain at a near constant-value. However, if the|Vds| is increased much further, then MOSFET will run away (i.e., breakdown), and the |Id| will be increased rapidly. Explain what causes the device to run away in terms of physical phenomena in the drain, source, channel and oxide under this |Vds| condition. ?