High-throughput ab initio calculations on dielectric constant and band gap of non-oxide dielectrics

High-k dielectrics, materials having a large band gap (E(g)) and high dielectric constant (k) simultaneously, constitute critical components in microelectronic devices. Because of the inverse relationship between E(g) and k, materials with large values in both properties are rare. Therefore, massive databases on E(g) and k will be useful in identifying optimal high-k materials. While experimental and theoretical data on E(g) and k of oxides are accumulating, corresponding information is scarce for non-oxide dielectrics with anions such as C, N, F, P, S, and Cl. To identify promising high-k dielectrics among these material groups, we screen 869 compounds of binary carbides, nitrides, sulfides, phosphides, chlorides, and fluorides, through automated ab initio calculations. Among these compounds, fluorides exhibit an E(g)-k relation that is comparable to that of oxides. By further screening over ternary fluorides, we identify fluorides such as BiF(3), LaF(3), and BaBeF(4) that could serve as useful high-k dielectrics.