Simulations of HfO2-SiO2 Interactions

[krishnabhattaram]

Dear ATK,

We're looking to do transport characterization for a large number of gate stacks between 150-250 atoms comprised of amorphous HfO2 and SiO2. We were hoping to use the semiempirical calculator since it's by far the fastest approach and we only need very rough DOS and band structure far from Ec, but it seems that no parameter sets are included for Hf-Si pairwise interaction. Is there a built-in approach to generate SK tight-binding parameters, perhaps from DFT simulations? Alternatively, is there a recommended approach for fast simulation of systems similar to ours with runtimes on the order of semiempirical approaches (perhaps a relatively simple pseudopotential with LCAO/DFT)?

Thank you,
Krishna

[Anders Blom]

In principle it might be possible to generate SK parameters for SiO2 and HfO2 separately, but I doubt one could get something that is even remotely accurate for the interface between them. DFTB might be an option, but the effort to fit parameters will be large. My recommendation would be to go with a cheap DFT-LCAO basis set like SingleZetaPolarized. Now, you don't write what properties you intend to compute, but obviously if the band gap is of importance, you don't want to rely just on GGA, but HSE will be very time-consuming, so for that I would recommend the TB09 MetaGGA approach.

[krishnabhattaram]

Got it, thank you for your help!