Interfacial engineering of ZrO₂ metal-insulator-metal capacitor using Al₂O₃/TiO₂ buffer layer for improved leakage properties

CHARACTERIZATION OF ENERGY BAND GAP THIN FILM BaTiO3 – BaZr0.5Ti0.5O3 USING DIFUSION REFLECTANCE SPECTROSCOPY (DRS) METHOD

“…Furthermore, ZrO2 is an insulator with an energy band gap of 5 eV and has the potential as an alternative material for in-memory storage capacitors. Besides its attractive electrical properties, ZrO2 thin film has attractive optical properties such as low light absorption, high refractive index, high transparency over a wide spectral range, and high threshold of field breakdown making it very good for laser optics [4][5][6][7][8][9][10][11][12][13].…”

Dielectric Constant Enhancement and Leakage Current Suppression of Metal–Insulator–Metal Capacitors by Atomic Layer Annealing and the Capping Layer Effect Prepared with a Low Thermal Budget

“…17,18 The introduction of an Al 2 O 3 interlayer into the oxide stack can suppress the leakage current. 23,24 However, it results in a decrease in the capacitance. 25 The crystallinity of ZrO 2 on the upper layer of Al 2 O 3 is deteriorated by the Al 2 O 3 interlayer, resulting in a decrease in the dielectric constant.…”

“…In recent decades, high- K dielectrics have been intensively studied to meet the specification of high-performance MIM capacitors. − Among the high- K dielectrics, ZrO 2 is attractive because of its high dielectric constant, large energy bandgap, and excellent compatibility with semiconductor fabrication processes. − However, it is difficult for a single ZrO 2 layer to achieve a low leakage current density due to the presence of vacancy-type defects (such as oxygen vacancies) while keeping a low EOT . Hence various oxide stack structures, such as ZrO 2 /Al 2 O 3 /ZrO 2 (ZAZ), , ZrO 2 /SiO 2 /ZrO 2 (ZSZ), , ZrO 2 /Y 2 O 3 /ZrO 2 (ZYZ), and ZrO 2 /La 2 O 3 /ZrO 2 (ZLZ), have been proposed and investigated, in which the ZAZ structure is the most widely used oxide stack in MIM capacitors in recent years. , The introduction of an Al 2 O 3 interlayer into the oxide stack can suppress the leakage current. , However, it results in a decrease in the capacitance . The crystallinity of ZrO 2 on the upper layer of Al 2 O 3 is deteriorated by the Al 2 O 3 interlayer, resulting in a decrease in the dielectric constant. , In order to get a good crystallinity of ZrO 2 overlying the Al 2 O 3 interlayer, the postannealing treatment at a temperature of ∼600 °C is usually needed. ,− Nevertheless, the high-temperature annealing leads to an increase in leakage current as a result of the generation of grain boundaries, which hinders the reduction of the oxide thickness in the MIM structure for further EOT scaling .…”