Tailoring dielectric relaxation in ultra-thin high-dielectric constant nanolaminates for nanoelectronics

Abstract

The work reported here demonstrates the feasibility of controlling the dielectric properties—high dielectric constant (k) and substantially extended relaxation frequency—of thin film nanolaminates (NLs) consisting of alternating TiOx and Al2O3 sublayers with various sublayer thicknesses grown by atomic layer deposition. For 150 nm thick TiOx/Al2O3 NLs with sub-nanometer thick sublayers, few Angstrom change in sublayer thickness dramatically increases relaxation cut-off frequency by more than 3 orders of magnitude with high dielectric constant (k > 800). This unusual phenomenon is discussed in the framework of two-phase Maxwell-Wagner relaxation.