Effect of thickness on surface morphology, optical and humidity sensing properties of RF magnetron sputtered CCTO thin films

Ahmadipour, Mohsen; Ain, Mohd Fadzil; Ahmad, Zainal Arifin

doi:10.1016/j.apsusc.2016.05.098

Cited by 49 publications

(12 citation statements)

References 29 publications

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“…Calcium copper titanate (CaCu 3 Ti 4 O 12 ), commonly referred to as CCTO, has gained much interest for being a potential candidate for microelectronic applications, such as capacitors, microwave devices, gas and humidity sensors, switching, energy storage devices, power systems and memory devices [1][2][3], mainly due to its extremely high dielectric permittivity (ε r ). Firstly discovered by Subramanian et al [4], the colossal dielectric constant of CCTO is of the order of 10 5 at room temperature, which is frequency independent in the 10 2 -10 6 Hz range and temperature insensitive from 100 to 600 K [2,5,6].…”

Section: Introductionmentioning

confidence: 99%

“…Several physical and chemical techniques have been used to deposit high-quality CCTO films, such as metal organic chemical vapour deposition (MOCVD), sol-gel method, chemical solution deposition, pulsed laser deposition (PLD) and radio frequency (RF) sputtering [3,6,9,12]. Among these techniques, RF-sputtering is the most accessible method due to several advantages: relatively cost-effective, low process temperature, easyto-control parameters, high deposition rate, uniform microstructure, scalability to large areas, homogeneity over large areas, reproducibility and very good stability [21,22].…”

Section: Introductionmentioning

confidence: 99%

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Evidence of ferroelectric behaviour in CaCu3Ti4O12 thin films deposited by RF-sputtering

Foschini

Hangai

Ortega

et al. 2019

PAC

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The origin of abnormal ferroelectric and unusual piezoelectricity in the polycrystalline CaCu 3 Ti 4 O 12 (CCTO) thin films deposited by RF-sputtering on Pt/Ti/SiO 2 /Si (100) substrates was explored. The CCTO thin films, deposited at room temperature followed by annealing at 600°C for 2 h in a conventional furnace, have a cubic structure with lattice parameter a = 7.379 ± 0.001 Å and without any secondary phases. No polarization loss up to 10 10 switching cycles, with a switched polarization ∆P of 30 µC/cm 2 measured at 400 kV/cm was evidenced. The piezoelectric coefficient investigated by piezoresponse force microscopy (PFM) was approximately 9.0 pm/V. This may be the very first example of exploring the origin of ferroelectric behaviour for a material that possesses space charge polarization with highly resistive grain boundaries in the polycrystalline state.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Evidence of ferroelectric behaviour in CaCu3Ti4O12 thin films deposited by RF-sputtering

Foschini

Hangai

Ortega

et al. 2019

PAC

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“…Most of the CCTO studies have focused on the preparation of bulk materials such as ceramics or single crystals using chemical methods and the identification of the possible mechanism regarding to its unique properties [10,11] However, thin layer have shown advantages over the bulk material for electronic applications [12][13][14]. The CCTO porous thin layer has been fabricated for different application such as humidity and gas sensor, dielectric constant applications [13,14]. It was reported that the properties of CCTO is dependent on the synthesis method as well as experimental conditions [15,16].…”

Section: Introductionmentioning

confidence: 99%

“…There are few studies available in the literature focusing on the fabrication of CCTO thin layer via RF magnetron sputtering process [12][13][14] to study the dielectric constant of gas sensors. However, the structural and physical properties of RF sputtered CCTO thin layer on Si wafer has not been discovered.…”

Section: Introductionmentioning

confidence: 99%

Deposition and Characteristics of Sputtered Coated CCTO Thin Layer on Silicon Wafer

Ahmadipour¹,

Ain²,

Ahmad³

2018

IJCRSET

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In the present study, the calcium copper titanate (CCTO) thin layer has been coated onto Si wafer at 300°C using a CCTO target by Radio Frequency (RF) magnetron sputtering in argon atmosphere. The surface morphology crystal structure was examined by X-ray diffraction (XRD), atomic force microscopy (AFM), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX), respectively. The CCTO layer revealed polycrystalline nature with characteristic peaks of (0 2 2), (2 2 4), and (0 2 4) at 34.19°, 54.75° and 61.29°. The average grain size and pore size of porous sputtered CCTO were determined as 20 nm and 15.70 nm, respectively.

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“…Due to the unique dielectric behavior of CCTO bulk ceramics, many research groups have initiated deposition of CCTO thin films by different deposition techniques [10][11][12][13][14][15][16] on various types of substrates [17][18][19]. Sputtering is considered as one of the most promising deposition technique for thin film deposition [20].…”

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Effect of RF sputtering power on morphological and electrical properties of calcium copper titanate thin films

Tripathy

Das

Ghosh

et al. 2017

J Mater Sci: Mater Electron

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dielectric constant, but these are limited to low temperature applications. Beyond the Curie temperature (T c ) their dielectric properties decreases dramatically, which is undesirable for device applications. Recently, CaCu 3 Ti 4 O 12 (CCTO), possessing a distorted cubic perovskite structure, has received intensive consideration due to its extraordinary dielectric behavior [7]. The dielectric constant of CCTO ceramics is in the order of 10 5 over a broad range of temperature due to its stable cubic structure [8] and also no lattice distortion has been observed in CCTO between this temperature range as confirmed by neutron diffraction and high resolution X-ray diffraction [7,8]. The origin of high permittivity in CCTO is still under debate. High dielectric behavior is the common feature in ferroelectric materials. In case of CCTO, the contribution from dipoles has been ruled out due to its centrosymmetry nature even at low temperature [7,8]. The internal barrier layer mechanism is widely accepted for explanation of giant dielectric permittivity in CCTO, where the conducting grains are separated by insulating grain boundaries [9]. Application of CCTO in microelectronics for memory devices, sensors, capacitor and varistors demands the deposition of CCTO thin films on silicon substrate.Due to the unique dielectric behavior of CCTO bulk ceramics, many research groups have initiated deposition of CCTO thin films by different deposition techniques [10-16] on various types of substrates [17][18][19]. Sputtering is considered as one of the most promising deposition technique for thin film deposition [20]. There are very few reports of deposition of CCTO thin film by RF sputtering [12,21]. Sputtering parameters like RF power, deposition pressure, substrate temperature strongly influence the structural, morphological and electrical properties of thin films. In our previous work [22], we have deposited CCTO thin film with the variation of deposition pressure on silicon Abstract Calcium copper titanate (CCTO) thin films were deposited on p-type silicon substrate by RF magnetron sputtering at various RF powers. Post deposition annealing was carried out for all the samples at 950 °C for 1 h in air atmosphere. Various types of surface morphology have been observed for CCTO thin films with the variation of RF power. The evolution of polycrystalline structure of the CCTO thin films was confirmed by XRD studies. The FTIR characteristic absorption band of CCTO was observed in the range of 400-700 cm −1 . The capacitancevoltage (C-V) and current-voltage (I-V) characteristics of the films were investigated employing Al/CCTO/Si MOS capacitors. CCTO films with higher dielectric constant, lower oxide and interface charge density were obtained at higher RF power. Leakage current was also found to be minimum for RF power of 105 W.

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Effect of thickness on surface morphology, optical and humidity sensing properties of RF magnetron sputtered CCTO thin films

Cited by 49 publications

References 29 publications

Evidence of ferroelectric behaviour in CaCu3Ti4O12 thin films deposited by RF-sputtering

Evidence of ferroelectric behaviour in CaCu3Ti4O12 thin films deposited by RF-sputtering

Deposition and Characteristics of Sputtered Coated CCTO Thin Layer on Silicon Wafer

Effect of RF sputtering power on morphological and electrical properties of calcium copper titanate thin films

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