Ab initio calculation of band alignment of epitaxial La2O3 on Si(111) substrate

AIMS Materials Science

Alberto Debernardi¹ 

[1] CNR-IMM, ss Agrate Brianza, via C. Olivetti 2, I-20864, Agrate Brianza, Italy, European Union;

关键词: High-k Oxides;    Lanthana;    Band-engineering;    ultra-scaled CMOS;    ab initio simulation;   

DOI  :  10.3934/matersci.2015.3.279

来源: DOAJ

【 摘 要 】

By means of plane wave pseudopotential method we have studied the electronic properties of the heterostructure formed by an high dielectric constant (k) oxide, the hexagonal La₂O₃ epitaxially grown with (0001)-orientation on Si (111) substrate. We found that for La₂O₃ both the dielectric constant along the growth direction and the band gap are larger in the epitaxial film than in the bulk. By super-cell techniques we have computed the band alignment of the junction finding a valence band offset and a conduction band offset of ~1.6 eV and ~1.7 eV respectively. We demonstrate that the band alignment can be engineered by δ-doping the interface: our simulations show that, by doping the interface with S or Se monolayer, the valence (conduction) band offset increases (decreases) of about 0.5 eV without the formation of spurious electronic states in the semiconductor band-gap. The simulation of the critical thickness of pseudomorphic Lanthana film complete the work. Our results are relevant for the realization of a new generation of devices based on ultra-scaled complementary metal oxides semiconductors (CMOS) technology.

【 授权许可】

Unknown