title: Ab initio design of high-k dielectrics: La(x)Y1-xAlO3.
abstract: We use calculations based on density-functional theory in the virtual crystal approximation for the design of high-k dielectrics, which could offer an alternative to silicon dioxide in complementary metal-oxide semiconductor devices. We show that aluminates LaxY1-xAlO3 alloys derived by mixing aluminum oxide with lanthanum and yttrium oxides have unique physical attributes for a possible application as gate dielectrics when stabilized in the rhombohedral perovskite structure, and which are lost in the orthorhombic modification. Stability arguments locate this interesting composition range as 0.2<x<0.4. Phase separation in microdomains is shown to have the tendency to further enhance the dielectric constant. We propose this as a novel family of high-k dielectrics deserving experimental exploration.
authors.affiliation: IBM Research, Zurich Research Laboratory, 8803 Rüschlikon, Switzerland.
authors.forename: Stephen A
authors.initials: SA
authors.lastname: Shevlin
authors.forename: Alessandro
authors.initials: A
authors.lastname: Curioni
authors.forename: Wanda
authors.initials: W
authors.lastname: Andreoni