Analysis of the degradation of PZT and SrBi2Ta2O9 thin films with a reductive process

Hase, Takashi; Noguchi, Takehiro; Miyasaka, Yoichi

doi:10.1080/10584589708013027

Cited by 60 publications

(18 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…With SBT, for example, peeling of the Pt electrode, a significant increase in leakage current, and a severe decrease in ferroelectric polarization were observed after the ''forming gas annealing step,'' which is usually done at 400-500°C in an H 2 -containing reducing atmosphere. 3,4 However, the degraded ferroelectric properties can be almost completely restored by subsequent annealing in oxygen. 3,4 Few studies have been done on the degradation and recovery of SBT capacitors made of Pt/SBT/Pt thin films.…”

mentioning

confidence: 99%

“…3,4 However, the degraded ferroelectric properties can be almost completely restored by subsequent annealing in oxygen. 3,4 Few studies have been done on the degradation and recovery of SBT capacitors made of Pt/SBT/Pt thin films. [3][4][5][6] Although compositional analysis by mass spectroscopy has suggested that oxygen defects 4 and Bi depletion 6 occur in SBT films annealed in an H 2 -containing reducing atmosphere, detailed mechanisms of the degradation and the recovery have not been clarified.…”

mentioning

confidence: 99%

“…3,4 Few studies have been done on the degradation and recovery of SBT capacitors made of Pt/SBT/Pt thin films. [3][4][5][6] Although compositional analysis by mass spectroscopy has suggested that oxygen defects 4 and Bi depletion 6 occur in SBT films annealed in an H 2 -containing reducing atmosphere, detailed mechanisms of the degradation and the recovery have not been clarified. To help us better understand the FeRAM device fabrication process, we have taken a solid-state chemistry approach using SBT bulk ceramic materials.…”

mentioning

confidence: 99%

See 2 more Smart Citations

Degradation of ferroelectric SrBi2Ta2O9 materials under reducing conditions and their reaction with Pt electrodes

Shimakawa

Kubo

1999

Applied Physics Letters

View full text Add to dashboard Cite

The degradation of ferroelectric SrBi2Ta2O9 in an H2-containing reducing atmosphere and its recovery by subsequent annealing in oxygen have been reproduced experimentally by using bulk ceramic samples. SrBi2Ta2O9 decomposes into Bi metal and Sr–Ta oxide(s) in H2 above 300 °C, and the decomposition rate increases as the annealing temperature rises. The recovery of SrBi2Ta2O9 is achieved through oxidation of Bi metal into β-Bi2O3, followed by a reaction of β-Bi2O3 and Sr–Ta oxide(s). In the presence of Pt, which is usually used as an electrode, the decomposition of SrBi2Ta2O9 is accelerated. Bi–Pt alloy and Bi–Pt oxide are produced under the reducing and oxidizing conditions, respectively. Our findings have important implications concerning the degradation of SrBi2Ta2O9 capacitors and the reaction between SrBi2Ta2O9 materials and Pt electrodes during thin-film device fabrication.

show abstract

mentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

See 1 more Smart Citation

Degradation of ferroelectric SrBi2Ta2O9 materials under reducing conditions and their reaction with Pt electrodes

Shimakawa

Kubo

1999

Applied Physics Letters

View full text Add to dashboard Cite

show abstract

“…Many groups have prepared SBT films by several techniques, such as pulsed laser deposition, 4,5 rf sputtering, 6 metalorganic chemical vapor deposition, 7 and by chemical solution, basically metalorganic decomposition 3,8,9 and the sol-gel process. 10,11 Several crystallization conditions, such as conventional ͑slow heating rates͒ 11 and rapid thermal annealing ͑RTA͒, 12,13 and pre-and post-annealing treatments 14,15 have been experimented.…”

Section: Introductionmentioning

confidence: 99%

Ferroelectric and microstructural characteristics of SrBi2Ta2O9 thin films crystallized by the rapid thermal annealing process

Zanetti

Bueno

Leite

et al. 2001

Journal of Applied Physics

View full text Add to dashboard Cite

O 9 thin films on Pt/Ti/SiO 2 /Si were successfully synthesized by the modified polymeric precursor method. The films were deposited by spin coating and crystallized by rapid thermal annealing in a halogen lamp furnace, followed by postannealing at temperatures ranging from 700°C to 800°C in an oxygen atmosphere. Microstructural and phase evaluations were followed by x-ray diffraction and atomic force microscopy. The films displayed spherical grain structures with a superficial roughness of approximately 3-6 nm. The dielectric constant values were 121 and 248 for films treated at 700°C and 800°C, respectively. The P -E curve showed a voltage shift toward the positive side, which was attributed to crystallization under the halogen illumination. The remanent polarization (2 P r ) and coercive field (E c ) were 7.1 C/cm 2 and 113 kV/cm, and 18.8 C/cm 2 and 93 kV/cm for the films treated at 700°C and 800°C, respectively.

show abstract

“…[3][4][5] H ϩ ions and electrons easily migrate in the ferroelectric material to form a space charge in response to the depolarizing field of the domains.…”

Section: Protection Of Srbi 2 Ta 2 O 9 Ferroelectric Capacitors From mentioning

confidence: 99%

Protection of SrBi2Ta2O9 ferroelectric capacitors from hydrogen damage by optimized metallization for memory applications

Hong

Suh

Lee

et al. 2000

Applied Physics Letters

View full text Add to dashboard Cite

The degradation behavior of integrated Pt/SrBi2Ta2O9/Pt capacitors by hydrogen impregnation during the intermetal dielectric deposition and passivation is investigated. The hydrogen ions generated as a reaction byproduct from the SiH4-based deposition processes of the dielectric films induce reduction in the remanent polarization (Pr) as well as the imprint behavior of the small size capacitors (2×2 μm2). The degree of degradation is quite dependent on the size of the individual capacitors. The smaller capacitors underwent more serious degradation implying that the hydrogen ions impregnate into the SBT layer mainly along the etched side area of the capacitors not through the top Pt electrode. Metallization adopting TiN/Al/TiN/Ti multilayer is very effective in suppressing the hydrogen impregnation. In particular, the Ti layer appears to block the hydrogen penetration. Therefore, the optimized metallization scheme, wider metal lines than the top electrode area by 1 μm, successfully protects the integrated capacitors from the hydrogen damage. 12 μC/cm2 of 2Pr and 1.1 V of 2Vc (coercive voltage) with an imprinting voltage of 0.16 V were obtained from the passivated 2×2 μm2 array capacitors by the optimized metallization.

show abstract

Analysis of the degradation of PZT and SrBi₂Ta₂O₉ thin films with a reductive process

Cited by 60 publications

References 6 publications

Degradation of ferroelectric SrBi2Ta2O9 materials under reducing conditions and their reaction with Pt electrodes

Degradation of ferroelectric SrBi2Ta2O9 materials under reducing conditions and their reaction with Pt electrodes

Ferroelectric and microstructural characteristics of SrBi2Ta2O9 thin films crystallized by the rapid thermal annealing process

Protection of SrBi2Ta2O9 ferroelectric capacitors from hydrogen damage by optimized metallization for memory applications

Contact Info

Product

Resources

About