Correct Answer - Option 2 : 1/β

Saturation current (Id_{ss}) for a MOSFET is given by:

\({I_{dss}} = \frac{{{C_0}\mu }}{2}\times\frac{W}{L}\times{\left( {{V_{gs}} - {V_t}} \right)^2}\)

C_{o} = Capacitance of the insulating material

W and L are the dimensions of the insulating layer

V_{gs} = Threshold voltage

Both V_{gs} & V_{t} are scaled by (1/β)

Both W & L scaled by (1/α)

C_{0} is scaled by ‘β’

∴ I_{dss} is scaled by:

\({I_{dss}} \Rightarrow β \times \frac{{1/\alpha }}{{1/\alpha }} \cdot {\left( {\frac{1}{β }} \right)^2}\)

⇒ 1/β