Thermal Stability of Neodymium Aluminates High-κDielectric Deposited by Liquid Injection MOCVD Using Single-Source Heterometallic Alkoxide Precursors

Abstract

Thin films of neodymium aluminate (NdAlO x ) have been deposited by liquid injection metalorganic chemical vapor deposition (MOCVD) using the bimetallic alkoxide precursor [NdAl(OPr i ) 6 (Pr i OH)] 2 . The effects of high-temperature postdeposition annealing on NdAlO x thin films are reported. The as-deposited thin films are amorphous in nature. X-ray diffraction (XRD) and medium energy ion scattering (MEIS) show, respectively, no crystallization or interdiffusion of metal ions into the substrate after annealing at 950 • C. The capacitance-voltage (C-V) and current-voltage (I-V) characteristics of the thin films exhibited good electrical integrity following annealing. The dielectric permittivity (κ) of the annealed NdAlO x was 12, and a density of interface states at flatband (D it ) of 4.01 × 10 11 cm −2 eV −1 was measured. The deposited NdAlO x thin films are shown to be able to endure high-temperature stress and capable of maintaining excellent dielectric properties.

Effects of thermal treatment and pH on electrical and physical properties of NdAlO3 dielectric thin films using sol–gel method

“…Compared with previous results for NdAlO 3 thin films with a leakage current density of ∼1 × 10 −7 A=cm 2 obtained by MOCVD, a leakage current density of 3.9 × 10 −7 A=cm 2 was obtained near an electric field of 30 kV=cm at a preheating temperature of 300 °C, pH 1.5, and an annealing temperature of 800 °C; such a value is close to the leakage current density obtained after the treatment. 12) The C-V behavior of NdAlO 3 thin films was measured for Ag=NdAlO 3 =Si=Ag (MIS) structures. By using the capacitance characteristic caused by the measuring process itself, the dielectric constant of the NdAlO 3 films could be calculated from the capacitances (Table I).…”

“…[5][6][7][8][9][10][11] In addition, they have also been widely used as high-k gate dielectric films because of their dielectric properties and stability with silicon substrates and substrates for superconducting microwave devices since they provide a high quality factor, excellent lattice matching, and good matching for thermal expansion. [12][13][14][15][16] NdAlO 3 also possesses excellent microwave dielectric properties and has a dielectric constant of 22.3 and a high Q × f value of 58000 GHz. 17) Many research studies were performed to improve the preparation and properties of NdAlO 3 ; however, most studies on NdAlO 3 have been limited to the bulk ceramic form.…”

Dielectric Relaxation, Modulus Behaviour and Conduction Mechanism in NdAlO3 Ceramics

“…14 Taechakumput annealing on the properties of NAO thin film, deposited by metal organic chemical vapor deposition using single-source precursor route. 15 The anti-Stokes white emission in NAO nanocrystal at ambient atmosphere was quite recently observed by Strek et al 16 Van der Laan et al 17,18 have studied the heat capacity of NAO from 0 K to 900 K. Using first-principles calculations, the enthalpy of formation for NAO has been predicted to be À41.1 kJ/mol-form. 19 However, to the best of our knowledge, a detailed investigation regarding the systematic study of the dielectric relaxation and conduction mechanism of NAO has not been performed.…”

Hysteresis in Lanthanide Aluminum Oxides Observed by Fast Pulse CV Measurement

“…In recent years, various high -k gate dielectrics have been investigated to find suitable alternative materials [5,6,7,8,9,10,11,12]. Significant progress has been made on the screening and selection of high -k gate dielectrics, understanding their physical properties, and their integration into CMOS technology [13,14,15,16,17,18,19,20]. Now it is recognized that a large family of oxide-based materials emerges as candidates to replace SiO 2 gate dielectrics in advanced CMOS applications [21,22,23,24,25,26].…”