QuantumATK Forum

QuantumATK => Scripts, Tutorials and Applications => Topic started by: Ash on May 2, 2012, 18:55

Title: Determining Work Function of Metallic/Dielectric Regions for Gate?
Post by: Ash on May 2, 2012, 18:55

Can someone tell me how to determine the work function of Metallic/Dielectric Regions used in Gate?

-- Thankyou

Title: Re: Determining Work Function of Metallic/Dielectric Regions for Gate?
Post by: esp on June 15, 2012, 05:10

i would like to know this as well, but i think the answer has to do also with the idea that for a specific work function of a metal, you would need to know the specific metal composition, and so the general purpose electrodes used in basic ATK calculations are not exactly real metals ... i think this is the correct understanding ... in other words, i believe it is true that if you want more information about the metal contacts, for example, you need to model specific contacts as you do the device area ... maybe there is a good example of this?

Title: Re: Determining Work Function of Metallic/Dielectric Regions for Gate?
Post by: Anders Blom on June 15, 2012, 10:10

You've nailed it. The gate electrodes are just electrostatic, and have no real "atomic" character, which would be needed to define a work function.

Title: Re: Determining Work Function of Metallic/Dielectric Regions for Gate?
Post by: Ash on June 18, 2012, 06:00

But without knowing the work function of this so called electrostatic region, how can one anticipate the changes of I-V as we move from two terminal to three terminal device with zero gate bias ?

Title: Re: Determining Work Function of Metallic/Dielectric Regions for Gate?
Post by: Anders Blom on June 18, 2012, 10:01

In principle yes, but this is only relevant if there is a gate current as well, but to describe such a real three-probe system you need the gate to be described atomistically as well, just as source and drain, and this formalism is not available in ATK.