Properties of Amorphous and Crystalline Ta2O5 Thin Films Prepared by Metalorganic Solution Deposition Technique for Integrated Electronic Devices

2000 ◽  
Vol 623 ◽  
Author(s):  
P.C. Joshi ◽  
M.W. Cole

AbstractWe report on the properties of Ta2O5 thin films prepared by the metalorganic solution deposition (MOSD) technique on Pt-coated Si, n+-Si, and poly-Si substrates. The effects of postdeposition annealing temperature on the structural, electrical, and optical properties were analyzed. The electrical measurements were conducted on MIM and MIS capacitors. The dielectric constant of amorphous Ta2O5 thin films was in the range 29.2-29.5 up to 600°C, while crystalline thin films, annealed in the temperature range 650–750°C, exhibited enhanced dielectric constant in the range 45.6–51.7. The dielectric loss factor did not show any appreciable dependence on the annealing temperature and was in the range 0.006–0.009. The films exhibited high resistivities of the order of 1012–1015 Δ-cm at an applied electric field of 1 MV/cm in the annealing temperature range of 500-750 °C. The temperature coefficient of capacitance was in the range 52-114 ppm/°C for films annealed in the temperature range 500-750°C. The bias stability of capacitance, measured at an applied electric field of 1 MV/cm, was better than 1.41 % for Ta2O5 films annealed up to 750°C.

1996 ◽  
Vol 446 ◽  
Author(s):  
David B. Beach ◽  
Catherine E. Vallet ◽  
Mariappan Paranthaman

AbstractAn all‐alkoxide route to SrBi2Ta2O9 (SBT) thin films and powders was developed. While stoichiometric gels transformed to single‐phase SBT, excess bismuth was required to obtain single‐phase SBT films on Pt substrates. An annealing temperature of 800 °C in O2 for 2 minutes was required to crystallize the films. Electrical measurements of SBT films produced under these conditions showed that films less than 2000 Å in thickness were shorted, while films of 3000 to 5000 Λ had a dielectric constant of~ 300. RBS measurements of a bismuth titanate film on Pt indicated that Pt diffuses into the dielectric layer when annealed at 700 °C in O2 for 1 minute, suggesting that interfacial reaction of these layered bismuth materials may be significant.


2012 ◽  
Vol 252 ◽  
pp. 211-215
Author(s):  
Xiao Hua Sun ◽  
Shuang Hou ◽  
Zhi Meng Luo ◽  
Cai Hua Huang ◽  
Zong Zhi Hu

Bismuth zinc niobate titanium (Bi1.5Zn0.5 Nb0.5Ti1.5O7) (BZNT) thin films were deposited on PtTiSiO2Si substrates by radio frequency (rf) magnetron sputtering. The microstructure, surface morphology, stress, dielectric and tunable properties of thin films were investigated as a function of initial annealing temperature. It’s found that high initial annealing temperature increases the grain size, dielectric constant and tunability of BZNT films simultaneously and decreases the tensile stress in films. The BZNT thin film annealed from 500 °C to 700 °C shows the highest FOM value of 45.67 with the smallest dielectric loss and upper tunability.


1999 ◽  
Vol 596 ◽  
Author(s):  
E. Ching-Prado ◽  
W. Pérez ◽  
P. S. Dobalt ◽  
R. S. Katiyart ◽  
S. Tirumala ◽  
...  

AbstractThin films of ferroelectric (SrBi2Ta2O9)x(Bi3TiNbO9)1-x layered structure (for x = 0.0, 0.2, … 1.0) were prepared by a metal organic solution deposition method on Pt/TiO2/SiO2/Si substrates. Raman spectroscopy, X-ray diffraction, atomic force microscopy (AFM), and electrical characterization techniques were utilized to study the inclusion of SrBi2Ta2O9 (SBT) in the Bi3TiNbO9 (BTN) system. The Raman spectra show frequency shifts and broadening of modes as x increases from 0.0 to 0.4, which are related to the nature of Sr and Bi in the A-sites, and Ta, Ti, and Nb in the B-sites. Smooth surfaces without any cracks or defects were evidenced in each of these films by AFM. These images also indicate that the grain size in the films increases with increasing SBT content in the BTN compound. Electrical measurements show that the remanent polarization (Pr) and the coercive field (Ec) values in the x=0.0 film (2 μC/cm2 and 30 kV/cm, respectively) increase to 12.5 μC/cm2 and 125 kV/cm for x=0.6. A decrease in these parameters was found for higher compositions.


2004 ◽  
Vol 268 (1-2) ◽  
pp. 198-203 ◽  
Author(s):  
Ai-Dong Li ◽  
Yi-Jun Wang ◽  
Su Huang ◽  
Jin-Bo Cheng ◽  
Di Wu ◽  
...  

2021 ◽  
Author(s):  
Yi Ye ◽  
Fengzhen Huang ◽  
Lin Lei ◽  
Lin Liu ◽  
Shuo Yan ◽  
...  

Abstract Electrocaloric effect (ECE) driven by electric field is suitable for implementation of built-in cooling in electronic devices. However, most of the known electrocaloric materials show low adiabatic temperature change ( ) near room temperature and usually require high electric field. Here, the investigation of ECE in Pb 1+x ZrO 3 (x=0, 0.1, 0.15) thin films, which were prepared on Pt/Ti/SiO 2 /Si substrates by sol-gel method, reveals that both the magnitude and the present temperature range of can be controlled by Pb concentration. Through increasing the dosage of PbO, decreased lead vacancies and enhanced interface layer are induced, which postpone the transition from antiferroelectrics to ferroelectrics of PbZrO 3 films under a given electric field ( E ), which thus controls the appearance temperature range of negative ECE. As a result, large isothermal entropy change ( and are observed in the temperature range from 260 K to 494 K, depending on the applied electric field and Pb concentration. Giant ECE ( , ~0.054) at room temperature (303 K) is obtained in Pb 1.1 ZrO 3 films under 460 kV/cm. This result provides a convenient method for modulating ECE of PbZrO 3 -based materials and will benefit its applications in cooling devices.


1997 ◽  
Vol 12 (4) ◽  
pp. 1160-1164 ◽  
Author(s):  
Nam-Kyeong Kim ◽  
Soon-Gil Yoon ◽  
Won-Jae Lee ◽  
Ho-Gi Kim

The microstructure and electrical properties were investigated for SrTiO3(STO) thin films deposited on Pt/Ti/SiO2/Si substrates by PEMOCVD. The SrF2 phase existing in the STO films deposited at 450 °C influences the dielectric constant, dissipation factor, and leakage current density of STO films. The dielectric constant and dissipation factor of STO films deposited at 500 °C were 210 and 0.018 at 100 kHz, respectively. STO films were found to have paraelectric properties from the capacitance-voltage characteristics. Leakage current density of STO films at 500 °C was about 1.0 × 10-8 A/cm2 at an electric field of 70 kV/cm. The leakage current behaviors of STO films deposited at 500 and 550 °C were controlled by Schottky emission with applied electric field.


2013 ◽  
Vol 745-746 ◽  
pp. 599-604 ◽  
Author(s):  
Xue Ying Chen ◽  
Lei Wang ◽  
Jin Bao Xu ◽  
Liang Bian ◽  
Bo Gao

Mn-Co-Ni-O (Mn:Co:Ni=1.74:0.72:0.54, MCN) thin films with single cubic spinel structure were prepared on Si substrates by metal organic solution deposition (MOSD) method at different annealing temperatures. The effects of annealing temperature on the phase component, crystalline microstructure, surface morphology and electrical properties of the MCN thin films were studied. According to the results of x-ray diffraction pattern, the MCN thin film annealed at 650 had spinel structure. Observation with field emission scanning electron microscope (FE-SEM) on the MCN thin films showed that the grain size increased with increasing annealing temperature. The resistance measured at room-temperature was 18.143, 12.457, 2.435 and 3.141MΩ for the MCN thin films annealed at 650, 700, 750 and 800, respectively. The values of thermistor constant (B30/85) and activation energy (Ea) were in the range of 3260-4840K and 0.28-0.42eV, respectively.


2001 ◽  
Vol 688 ◽  
Author(s):  
Kazunari Maki ◽  
Nobuyuki Soyama ◽  
Kaoru Nagamine ◽  
Satoru Mori ◽  
Katsumi Ogi

AbstractWe studied the crystallization of sol-gel derived Pb(Zr0.4Ti0.6)O3 [PZT(40/60)] thin films at 400 down to 390°C on Pt/SiO2/Si substrates by combination of diol-based solutions and modified film preparation processes. It was found that PZT films could be crystallized at 390°C and that PZT films crystallized at 400°C had microstructures with perovskite-single-phase columnar grains and good ferroelectric characteristics such as switched polarization (2 Pr) of 20 μC/cm2 and relative permittivity (εr) of 740. Next, we evaluated annealing temperature dependence of PZT(40/60) thin films crystallized at 390 to 435°C. The results indicated that (111)-orientation of perovskite phases became weaker, (100)-orientation of those became stronger, and the perovskite grain size increased with decreasing in annealing temperature.


2011 ◽  
Vol 197-198 ◽  
pp. 1781-1784
Author(s):  
Hua Wang ◽  
Jian Li ◽  
Ji Wen Xu ◽  
Ling Yang ◽  
Shang Ju Zhou

Intergrowth-superlattice-structured SrBi4Ti4O15–Bi4Ti3O12(SBT–BIT) films prepared on p-Si substrates by sol-gel processing. Synthesized SBT–BIT films exhibit good ferroelectric properties. As the annealing temperature increases from 600°C to 700°C, the remanent polarization Prof SBT–BIT films increases, while the coercive electric field Ecdecreases. SBT–BIT films annealed at 700°C have a Prvalue of 18.9µC/cm2which is higher than that of SBT (16.8µC/cm2) and BIT (14.6µC/cm2), and have the lowest Ecof 142 kV/cm which is almost the same as that of SBT and BIT. The C-V curves of Ag/SBT-BIT/p-Si heterostructures show the clockwise hysteresis loops which reveal the memory effect due to the polarization. The memory window in C-V curve of Ag/SBT-BIT/p-Si is larger than that of Ag/SBT/p-Si heterostructure or Ag/BIT/p-Si heterostructure.


1999 ◽  
Vol 606 ◽  
Author(s):  
S. Bhaskar ◽  
S. B. Majumder ◽  
P. S. Dobal ◽  
R. S. Katiyar ◽  
A. L. M. Cruz ◽  
...  

AbstractIn the present work we have optimized the process parameters to yield homogeneous, smooth ruthenium oxide (RuO2) thin films on silicon substrates by a solution deposition technique using RuCl3.×.H2O as the precursor material. Films were annealed in a temperature range of 300°C to 700°C, and it was found that RuO2 crystallizes at a temperature as low as 400°C. The crystallinity of the films improves with increased annealing temperature and the resistivity decreases from 4.86µΩ-m (films annealed at 400°C) to 2.94pµΩ (films annealed at 700°C). Ageing of the precursor solution has a pronounced effect on the measured resistivities of RuO2 thin films. It was found that the measured room temperature resistivities increases from 2.94µΩ-m to 45.7µΩ-m when the precursor sol is aged for aged 60 days. AFM analysis on the aged films shows that the grain size and the surface roughness of the annealed films increase with the ageing of the precursor solution. From XPS analysis we have detected the presence of non-transformed RuCl3 in case of films prepared from aged solution. We propose, that solution ageing inhibits the transformation of RuCl3 to RuO2 during the annealing of the films. The deterioration of the conductivity with solution ageing is thought to be related with the chloride contamination in the annealed films.


Sign in / Sign up

Export Citation Format

Share Document