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

摘要

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 TiO_x and Al_2O_3 sublayers with various sublayer thicknesses grown by atomic layer deposition. For 150 nm thick TiO_x/Al_2O_3 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.