Leakage Current of PLD- and CSD-BiFeO3 Thin Films Observed by Current Sensitive AFM

2009 ◽  
Vol 1199 ◽  
Author(s):  
Seiji Nakashima ◽  
Hironori Fujisawa ◽  
Jung Min Park ◽  
Takeshi Kanashima ◽  
Masanori Okuyama ◽  
...  

AbstractWe have investigated relationships between leakage current and microstructure or domain structure of BiFeO3 (BFO) thin films, and leakage current mappings of BFO thin films have been performed by current sensitive AFM. 350-nm-thick and 250-nm-thick BFO thin films were prepared on Pt/TiO2/SiO2/Si substrate by pulsed laser deposition (PLD) and chemical solution deposition (CSD), respectively. Average grain size of PLD-BFO thin film is about 480 nm, which is the same as the film thickness. From the leakage current mapping at a bias voltage of -16 Vdc, leakage current of the BFO thin film flows through not only grain boundary but also the grain itself. On the other hand, CSD-BFO thin film shows rosette structure and small size grains. From the leakage current mapping at a bias voltage of -10 Vdc, leakage current flows along boundaries of the rosette structures. These results indicate that leakage current of BFO strongly depends on its microstructure.

2019 ◽  
Vol 26 (03) ◽  
pp. 1850166 ◽  
Author(s):  
HUITING SUI ◽  
HUAJUN SUN ◽  
XIAOFANG LIU ◽  
SHANSHAN GUO ◽  
HUAN YANG ◽  
...  

BiFe[Formula: see text]CrxO3 ([Formula: see text]BFCO, [Formula: see text], 0.02, 0.03, 0.04, 0.05) thin films were successfully fabricated onto Pt(111)/TiO2/SiO2/Si substrate via a solgel process. The correlation between microstructure and insulating, ferroelectric properties of [Formula: see text]BFCO thin films are investigated. The leakage behavior for all the thin films is in accordance with the Ohmic conduction and FN Tunneling emission during low and high electric field region, respectively. Compared with the pure BFO, all the thin films with Cr[Formula: see text] doping possess reduced leakage current density by 1–2 orders of magnitude, with the lowest value approximately 10[Formula: see text] at 200[Formula: see text]kV/cm. Moreover, the 0.04BFCO thin film exhibits the maximum remanent polarization ([Formula: see text]) value of 29.8[Formula: see text][Formula: see text]C/cm2 with a great fatigue behavior, which could be ascribed to the absence of impurity phase and reduced leakage current.


2014 ◽  
Vol 602-603 ◽  
pp. 800-803
Author(s):  
Min Chang Kuan ◽  
Fann Wei Yang ◽  
Chien Min Cheng ◽  
Kai Huang Chen ◽  
Jian Tz Lee

Lead-free potassium sodium niobate ceramic thin films were synthesized using rf magnetron sputtering technology for MFIS structures. The optimal sputtering parameters of the as-deposited KNN thin films for depositing times of 1h were obtained. Regarding the measured physical properties, the micro-structure and thickness of as-deposited KNN thin films for different oxygen concentration were obtained and compared by XRD patterns and SEM images. The surface roughness of KNN thin film was also observed by AFM morphology. The average grain size and root mean square roughness were 250 and 7.04 nm, respectively. For KNN thin films in the MFIS structure, the capacitance and leakage current density were 280 pF and 10-8A/cm2, respectively. We investigated that the leakage current density and the memory window increased, the capacitance critically increased as the oxygen concentration increased from 0 to 40%. However, the excess oxygen concentration process was decreased the electrical and physical of as-deposited KNN thin film. The effect of oxygen concentration on the physical and electrical characteristics of KNN thin films was investigated and determined.


2011 ◽  
Vol 239-242 ◽  
pp. 532-535
Author(s):  
Chien Min Cheng ◽  
Shih Fang Chen ◽  
Jen Hwan Tsai ◽  
Kai Huang Chen ◽  
Hsiu Hsien Su

Lead-free potassium sodium niobate ceramic thin films were synthesized using rf magnetron sputtering technology for MFIS structures. The optimal sputtering parameters of the as-deposited KNN thin films for depositing times of 1h were obtained. Regarding the measured physical properties, the micro-structure and thickness of as-deposited KNN thin films for different oxygen concentration were obtained and compared by XRD patterns and SEM images. The surface roughness of KNN thin film was also observed by AFM morphology. The average grain size and root mean square roughness were 250 and 7.04 nm, respectively. For KNN thin films in the MFIS structure, the capacitance and leakage current density were 280 pF and 10-8A/cm2, respectively. We investigated that the leakage current density and the memory window increased, the capacitance critically increased as the oxygen concentration increased from 0 to 40%. However, the excess oxygen concentration process was decreased the electrical and physical of as-deposited KNN thin film. The effect of oxygen concentration on the physical and electrical characteristics of KNN thin films was investigated and determined.


Scanning ◽  
2018 ◽  
Vol 2018 ◽  
pp. 1-5 ◽  
Author(s):  
Jin Jeong

SnO2 thin films grown directly on the Si substrate had larger average grain sizes as the power intensity increased, but the average grain size of the SnO2 thin films grown in oxygen atmosphere decreased as the power intensity increased. Hall measurement of pure SnO2 thin films showed that the carrier density increased with increasing power. However, upon annealing the SnO2 thin films, the carrier density decreased with increasing power owing to the formation of oxygen vacancies and the SiO2 layer between the Si substrate and SnO2 thin films. The photoluminescence (PL) of the SnO2 thin film grown in the oxygen atmosphere changed, and it was affected by the oxygen defects at the surface and interfaces of the thin film.


2020 ◽  
Vol 20 (11) ◽  
pp. 7158-7162
Author(s):  
Ji-Won Kim ◽  
Sung-Gap Lee ◽  
Kyeong-Min Kim ◽  
Ji-Su Yuk ◽  
Joo-Seok Park

In this study, KTa0.55Nb0.45O3 (KTN) thin films were manufactured by using Chemical Solution Deposition (CSD) method with variations in the sintering temperature and were investigated in order to apply their applicability in memory devices. The KTN thin films were made after coating the PZT bufferlayer on Pt/Ti/SiO2/Si substrate. Each layer was dried at 200°C for 5 min to remove any organic materials and pyrolyzed at 400°C for 10 min. Finally, the layers were sintered for 30 min under an oxygen atmosphere, respectively. The pattern of KTN thin films showed a preference to the (100) and (200) orientations. Also, an increase in the sintering temperature caused the KTN crystalline peak intensities to also increase. When looking at the results from the Scanning Electron Microscope and Atomic Force Microscope data, the average grain size and root mean square roughness (Rrms) of KTN thin films were 109~157 nm and about 4 nm, respectively. Typical dielectric dispersion characteristics were observed in which the dielectric constant decreases with an increase of the applied frequency. The specimen sintered at 750°C showed the highest dielectric constant of 769 at 1 kHz.


2012 ◽  
Vol 512-515 ◽  
pp. 1372-1375 ◽  
Author(s):  
Fann Wei Yang ◽  
Chien Min Cheng ◽  
Kai Huang Chen

Lead-free potassium sodium niobate ceramic thin films were synthesized using rf magnetron sputtering technology for MFIS structures. The optimal sputtering parameters of the as-deposited KNN thin films for depositing times of 1h were obtained. Regarding the measured physical properties, the micro-structure and thickness of as-deposited KNN thin films for different oxygen concentration were obtained and compared by XRD patterns and SEM images. The surface roughness of KNN thin film was also observed by AFM morphology. The average grain size and root mean square roughness were 250 and 7.04 nm, respectively. For KNN thin films in the MFIS structure, the capacitance and leakage current density were 280 pF and 10-8A/cm2, respectively. We investigated that the leakage current density and the memory window increased, the capacitance critically increased as the oxygen concentration increased from 0 to 40%. However, the excess oxygen concentration process was decreased the electrical and physical of as-deposited KNN thin film. The effect of oxygen concentration on the physical and electrical characteristics of KNN thin films was investigated and determined.


Coatings ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 23
Author(s):  
Weiguang Zhang ◽  
Jijun Li ◽  
Yongming Xing ◽  
Xiaomeng Nie ◽  
Fengchao Lang ◽  
...  

SiO2 thin films are widely used in micro-electro-mechanical systems, integrated circuits and optical thin film devices. Tremendous efforts have been devoted to studying the preparation technology and optical properties of SiO2 thin films, but little attention has been paid to their mechanical properties. Herein, the surface morphology of the 500-nm-thick, 1000-nm-thick and 2000-nm-thick SiO2 thin films on the Si substrates was observed by atomic force microscopy. The hardnesses of the three SiO2 thin films with different thicknesses were investigated by nanoindentation technique, and the dependence of the hardness of the SiO2 thin film with its thickness was analyzed. The results showed that the average grain size of SiO2 thin film increased with increasing film thickness. For the three SiO2 thin films with different thicknesses, the same relative penetration depth range of ~0.4–0.5 existed, above which the intrinsic hardness without substrate influence can be determined. The average intrinsic hardness of the SiO2 thin film decreased with the increasing film thickness and average grain size, which showed the similar trend with the Hall-Petch type relationship.


2001 ◽  
Vol 688 ◽  
Author(s):  
H. Uchida ◽  
H. Yoshikawa ◽  
I. Okada ◽  
H. Matsuda ◽  
T. Iijima ◽  
...  

AbstractBismuth titanate (Bi4Ti3O12; BIT) -based ferroelectric materials are proposed from the view of the “Site-engineering”, where the Bi-site ions are substituted by lanthanoid ions (La3+ and Nd3+) and Ti-site ions by other ions with higher charge valence (V5+). In the present study, influences of vanadium (V) - substitution for (Bi,M)4Ti3O12 thin films [M = lanthanoid] on the ferroelectric properties are evaluated. V-substituted (Bi,M)4Ti3O12 films have been fabricated using a chemical solution deposition (CSD) technique on the (111)Pt/Ti/SiO2/(100)Si substrate. Remnant polarization of (Bi,La)4Ti3O12 and (Bi,Nd)4Ti3O12 films has been improved by the V-substitution independent of the coercive field. The processing temperature of BLT and BNT films could also be lowered by the V-substitution.


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