cmos bjt
1)In MOSFET output current depends on square of input voltage whereas in case of BJT ouput current linearly depends on input current
from above said point ,
MOSFET is a square law device(bcoz of this we are using it as a MIXER in commn)
BJT is a not square law device
Also, We can say that MOSFET is current controlled voltage device where BJT IS current controlled current device
2)in BJT EMIITER BASE and COLLECTOR will have there own doping concentration (NON UNIFORMITY )whereas in case of MOSFET doping will be uniform so we can interchange source with drain whereas in BJT it is not possible.
3) since MOSFET is working based rev.bias on its input side ,its input imp. is very higher .so it will have less loading effect whereas in BJT loading effect will occur
4)MOSFET is high immunity toward s radiation but BJT less immunity for radiation(i havin g no prove for this)
5) MOSFET IS HAVING LESS GAIN BANDWIDTH PRODUCT THAN BJT
ie BJT can be used for high freq. applications
6)PROBLEM OF ESR IN MOSFET