ZIRCONIUM SUBSTITUTED BARIUM TITANATE GATE DIELECTRICS

摘要

The use of atomic layer deposition (ALD) to form a zirconium substituted layerof barium titanium oxide (BaTiO3), produces a reliable structure for use in avariety of electronic devices such as a dielectric in nonvolatile random accessmemories (NVRAM), tunable dielectrics for multi layer ceramic capacitors (MLCC),infrared sensors and electro-optic modulators. The structure is formed by depositingalternating layers of barium titanate and barium zirconate by ALD on a substratesurface using precursor chemicals, and repeating to form a sequentially depositedinterleaved structure of desired thickness and composition. Such a layer maybe used as the gate insulator of a MOSFET, or as a capacitor dielectric. The propertiesof the dielectric may be tuned by adjusting the percentage of zirconium to titaniumto optimize properties such as a dielectric constant, Curie point, film polarization,ferroelectric property and a desired relaxor response.