How a high-k gate dielectric in place of low-k dielectric in device design increases the electric field? Is there any relation between dielectric constant and electric field of a gate capacitance?
yes there a relation between dielectric constant and electric field of a gate capacitance. and it can be mathematically given as: For further clarification see the paper i have sent to u. furthermore the capacitance is dependent on dielectric constant of the gate dielectric used.
Dear Sumit,
High k materials is used ti increase the MOS capacitance per unit area as C= epsilon/tdielect, where epsilon is the dielectric constant and tdielect is the thickness of the dielelctric .
The charge on the capacitor Q= C V, where V is the applied voltage.
One can write Q= epsilon V/ tdielectric= epsilon E,
Then E= V/tdielectric
From this relation it is clear that the electric field is independent of epsilon of the material. It depends on the voltage and distance between the two electrodes.
This is known fact in the electrostatics the electric field is the gradient of the potential. But the displacement D=Q which depends on epsilon and namely it is proportional to epsilon.
Best wishes
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