Ab-initio study of energetics of the Si(001)-LaAlO3 interface

作者：Sen Dipanjan; Windl Wolfgang^*

来源：Journal of Computational and Theoretical Nanoscience, 2007, 4(1): 57-64.

• nanoelectronics
• high-k dielectrics
• first-principles modeling
• chemical potential prediction
• LaAlO3
• interface stability

Ab-initio electronic structure calculations are used to find the energetically preferred interface of crystalline LaAlO3 and Si(001), which is a potential materials combination in nanoscale electronic devices. We calculate the interfacial free energy allowing for different growth conditions with varying oxygen pressures. We find that the lowest-energy interface is for LaO terminated (001) LaAlO3 in contact with the Si(001) surface. The lowest-energy configuration for the latter can either be (2 x 1) reconstructed or unreconstructed, depending on the atomic configuration on the LaAlO3 side. We also find that La and O-deficiencies in bulk LaAlO3 can make the AlO2 termination energetically competitive. Depending on oxygen partial pressure during deposition of LaAlO3 we find that the La layer at the interface should be partially La deficient with varying stoichiometry or perfectly stoichiometric.

• 出版日期2007-1