Fabrication of 3-Dimensional PbZr1−x TixO3 Nanoscale Thin Film Capacitors for High Density Ferroelectric Random Access Memory Devices

2006 ◽  
Vol 6 (11) ◽  
pp. 3333-3337 ◽  
Author(s):  
Sangmin Shin ◽  
June-Mo Koo ◽  
Sukpil Kim ◽  
Bum-Seok Seo ◽  
Jung-Hyun Lee ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Remnant Polarization ◽  
Random Access ◽  
Switching Behavior ◽  
Pzt Thin Films ◽  
3 Dimensional ◽  
Thin Film Capacitors ◽  
Pattern Size ◽  
20 Nm

PbZrx Ti1−xO3 (PZT) thin films were deposited on 3-dimensional (3D) nano-scale trench structures for use in giga-bit density ferroelectric random access memories. PZT thin films were deposited by liquid delivery metalorganic chemical vapor deposition using Pb(thd)2, Zr(MMP)4, and Ti(MMP)4 precursors dissolved in ethyl cyclohexane. Iridium thin films were deposited by atomic layer deposition, and they exhibited excellent properties for capacitor electrodes even at a thickness of 20 nm. The trench capacitor was composed of three layers, viz. Ir/PZT/Ir (20/60/20 nm), and had a diameter of 250 nm and a height of 400 nm. Almost 100% step coverage was obtained at a deposition temperature of 530 °C. The PZT thin film capacitors with a thickness of 60 nm on a planar structure exhibited a remnant polarization (Pr of 28 μC/cm2, but the Pr value of the 3D PZT capacitors decreased slightly with decreasing 3D trench pattern size. The transmission electron microscope analysis indicated that the PZT thin films had compositional uniformity in the 3D trench region. Both columnar and granular grains were formed on the sidewalls of the trench capacitors, and their relative proportion exhibited strong size dependence. The trench capacitors with more columnar PZT grains showed good switching behavior under an external bias of 2.1 V and had a remnant polarization of 19 ∼ 24 μC/cm2.

Effect of La Dopant on Electrical Properties of Pb(Zr,Ti)O3 Thin Film Capacitors

1999 ◽  
Vol 596 ◽  
Author(s):  
Chang Jung Kim ◽  
Ilsub Chung
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Electrical Properties ◽  
Lead Zirconate Titanate ◽  
Random Access ◽  
Lead Zirconate ◽  
Second Phase ◽  
Pzt Thin Films ◽  
Si Substrates ◽  
Thin Film Capacitors

AbstractLanthanum doped lead zirconate titanate (PZT) thin films have been prepared on Pt/IrO2/Ir/SiO2/Si substrates to improve the ferroelectric and retention properties. The microstructure and electrical properties of the PZT capacitors were evaluated as a function of La content. The crystalline orientation was appreciably influenced by the addition of La in PZT thin films. The microstructures of films containing 0 and 0.5 mol% La were single phase perovskite, but for La = 1 mol%, a second phase was detected by SEM observation. The 0.5 mol% La doped PZT thin film capacitor showed the best ferroelectric and retention properties for ferroelectric random access memory compared to non-doped PZT.

scholarly journals High performance, electroforming-free, thin film memristors using ionic Na0.5Bi0.5TiO3

2021 ◽  
Vol 9 (13) ◽  
pp. 4522-4531
Author(s):  
Chao Yun ◽  
Matthew Webb ◽  
Weiwei Li ◽  
Rui Wu ◽  
Ming Xiao ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Resistive Switching ◽  
Growth Temperature ◽  
High Performance ◽  
20 Nm

Interfacial resistive switching and composition-tunable RLRS are realized in ionically conducting Na0.5Bi0.5TiO3 thin films, allowing optimised ON/OFF ratio (>104) to be achieved with low growth temperature (600 °C) and low thickness (<20 nm).

scholarly journals Nanostructure Analysis of Sol-gel PZT Thin Films Derived from Different Chemical Routes

2009 ◽  
Vol 15 (S3) ◽  
pp. 53-54
Author(s):  
Aiying Wu ◽  
P. M. Vilarinho
Keyword(s):  
Thin Films ◽  
Data Storage ◽  
Chemical Reactivity ◽  
Sol Gel ◽  
Random Access ◽  
Lead Zirconate ◽  
Piezoelectric Response ◽  
Metal Alkoxides ◽  
Pzt Thin Films ◽  
Wide Range

AbstractLead zirconate - lead titanate (PZT) materials are commercially important piezoelectric and ferroelectrics in a wide range of applications, such as data storage (dynamic access and ferroelectric random access memories) and sensing and actuating devices. PZT with the morphotropic phase boundary composition offers the highest piezoelectric response and at the present there are no fullydeveloped alternative materials to PZT. The importance of PZT associated with the continuous requirements of device miniaturization, imposes the development of high quality PZT thin films with optimized properties. Concomitantly due to the dependence of the final properties of thin films on the details of the microstructure a thoroughly analysis at the local scale of their microstructure is necessary. Sol-gel method, is one of the Chemical Solution Deposition techniques used to prepare oxide thin films, such as PZT. Starting from a solution, a solid network is progressively formed via inorganic polymerisation reactions. Most metal alkoxides used for sol-gel synthesis are highly reactive towards hydrolysis and condensation. Therefore their chemical reactivity has to be tailored via the chemical modification (or complexation) of metal alkoxides to avoid uncontrolled reactions and precipitation. For PZT sol gel thin film preparation, two chemical routes are frequently used depending on the nature of the molecular precursor, namely methotoxyethanol (MOE) route and diol-route.

Bipolar Switching Properties of the Manganese Oxide Thin Film RRAM Devices

2014 ◽  
Vol 602-603 ◽  
pp. 1056-1059 ◽  
Author(s):  
Min Chang Kuan ◽  
Fann Wei Yang ◽  
Chien Min Cheng ◽  
Kai Huang Chen ◽  
Jian Tz Lee
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Manganese Oxide ◽  
Random Access ◽  
Random Access Memory ◽  
Memory Devices ◽  
Access Memory ◽  
Resistance Random Access Memory ◽  
Non Volatile Memory ◽  
Volatile Memory

Up to now, the various non-volatile memory devices such as, ferroelectric random access memory (FeRAM), magnetron random access memory (MRAM), and resistance random access memory (RRAM) were widely discussed and investigated. For these nonvolatile memory devices, the resistance random access memory (RRAM) devices will play an important role because of its non-destructive readout, low operation voltage, high operation speed, long retention time, and simple structure. The resistance random access memory (RRAM) devices were only consisting of one resistor and one corresponding transistor. The subject of this work was to study the characteristics of manganese oxide (MnO) thin films deposited on transparent conductive thin film using the rf magnetron sputtering method. The optimal sputtering conditions of as-deposited manganese oxide (MnO) thin films were the rf power of 80 W, chamber pressure of 20 mTorr, substrate temperature of 580°C, and an oxygen concentration of 40%. The basic mechanisms for the bistable resistance switching were observed. In which, the non-volatile memory and switching properties of the manganese oxide (MnO) thin film structures were reported and the relationship between the memory windows and electrical properties was investigated.

Effect of Annealing Treatment on PZT Thin Fiilm Properties Using Oxygen 18 Depth Profiling Technique

1998 ◽  
Vol 541 ◽  
Author(s):  
F. Ayguavives ◽  
B. Ea-Kim ◽  
B. Agius ◽  
I. Vickridge ◽  
A. I. Kingon
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Lead Zirconate Titanate ◽  
Plasma Deposition ◽  
Annealing Treatment ◽  
Nuclear Reaction Analysis ◽  
Nominal Composition ◽  
Pzt Thin Films ◽  
Pzt Thin Film ◽  
Metallic Target

AbstractLead zirconate titanate (PZT) thin films have been deposited in a reactive argon/oxygen gas mixture from a metallic target of nominal composition Pb1.1(Zr0.4Ti0.6)O3 by rf magnetron sputtering on Si substrates and RuO2/SiO2/Si structures. During plasma deposition, in situ Optical Emission Spectroscopy (OES) measurements clearly show a correlation between the evolution of characteristic atomic emission line intensities and the thin film composition determined by simultaneous Rutherford Backscattering Spectroscopy (RBS) and Nuclear Reaction Analysis (NRA). As a result, the cathode surface state can be monitored by OES to ensure a good compositional transferability from the target to the film and reproducibility of thin film properties for given values of deposition parameters. Electrical properties and crystallization have been optimized with a 90 nm PZT thin film grown on RuO2 electrodes. These PZT films, annealed with a very modest thermal budget (550°C) are fatigue-free and show very low leakage currents (J=2.10−8 A/cm2 at 1 V). The use of a metallic target allows us to control the oxygen incorporation in the PZT thin film and also, using 18O as a tracer, to study the oxygen vacancy migration which plays a key role in fatigue, leakage current, and electrical degradation/breakdown in PZT thin films.

The Microstructure, Phase and Ferroelectric Properties of PZT Thin Films on Oriented Multilayer Electrodes

1999 ◽  
Vol 596 ◽  
Author(s):  
Tingkai Li ◽  
Sheng Teng Hsu ◽  
Yufei Gao ◽  
Mark Engelhard
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Hysteresis Loop ◽  
Perovskite Phase ◽  
Ferroelectric Properties ◽  
Pyrochlore Phase ◽  
Experimental Results ◽  
Butyl Ether ◽  
Pzt Thin Films ◽  
Pzt Thin Film

AbstractThree kinds of oriented electrodes of Pt, Ir and Pt/Ir electrodes were prepared using electron beam evaporation techniques for deposition of PZT thin films. An oxide MOCVD reactor with liquid delivery system was used for the growth of PZT thin films. [Pb(thd)2], Zr(TMHD)4 and Ti(IPO)4 were dissolved in a mixed solvent of tetrahydrofuran or butyl ether, isopropanol and tetraglyme to form a precursor source. The deposition temperature and pressure were 500 - 650°C and 5 - 10 Torr, respectively. The experimental results showed PZT thin film deposited on various electrodes had different phase formation, microstructure and ferroelectric property. The X-ray patterns showed the perovskite phase of PZT was formed on both Ir and Pt/Ir electrodes at 550°C. The grain size of the PZT thin film increases after a further, higher temperature annealing. The as-deposited PZT thin film on Pt electrode exhibits pyrochlore phase at 550°C. The phase is transformed to perovskite phase after 650°C annealing. The experimental results also indicated that the MOCVD PZT thin film on Pt/Ir exhibits better ferroelectric and electrical properties compared to those deposited on Pt and Ir electrodes. A 300 nm thick PZT thin film on Pt/Ir electrode has a square, well saturated, and symmetrical hysteresis loop with 2Pr value of 40 μC/cm2 and 2Ec of 73 kV/cm at an applied voltage of 5 V. The hysteresis loop of the PZT thin film is almost saturated at 2 V. The leakage current of the film is 6.16 × 10−7 A/cm2 at 100 KV/cm. The electrode effects on ferroelectric properties of PZT thin films also have been investigated.

PZT Thin Films Deposited by RF Magnetron Sputtering

2013 ◽  
Vol 302 ◽  
pp. 8-13
Author(s):  
Shun Fa Hwang ◽  
Wen Bin Li
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Annealing Temperature ◽  
Bottom Electrode ◽  
Rf Sputtering ◽  
Rf Magnetron Sputtering ◽  
Pzt Thin Films ◽  
Pzt Film ◽  
Pzt Thin Film

PZT thin film was fabricated by using RF-sputtering process, and platinum was used as bottom electrodes. The sputtering gases were Ar：O2＝25：0 sccm, Ar：O2＝20：5 sccm, or Ar：O2＝15：10 sccm. After sputtering, the PZT film was annealed for 5 minutes under O2 gas environment and at the temperature of 600 0C, 650 0C, 700 0C or 750 0C. To judge the quality of the deposited PZT film, its physical properties and electric properties were evaluated. The results indicate that the best crystallization temperature of PZT thin film is about 700 0C. Also, the roughness of the PZT thin film becomes larger with the increasing of annealing temperature. By adding more oxygen in the sputtering gas, one could have better crystallization of the PZT film. As for the electrical properties, the leakage current of PZT thin film increases with the increasing of annealing temperature. Furthermore, the ferroelectric property is affected by the crystallization amount of perovskite, the thickness of PZT thin film, and the diffusion situation between the bottom electrode and the PZT film.

Measuring Fatigue in PZT Thin Films

1990 ◽  
Vol 200 ◽  
Author(s):  
D. J. Johnson ◽  
D. T. Amm ◽  
E. Griswold ◽  
K. Sreenivas ◽  
G. Yi ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Dielectric Permittivity ◽  
Dielectric Response ◽  
Remanent Polarization ◽  
Small Signal ◽  
Large Signal ◽  
Pzt Thin Films ◽  
Pzt Thin Film

ABSTRACTSmall signal dielectric response is reported for a variety of PZT thin film samples. Small and large signal responses, recorded simultaneously during the fatiguing of PZT thin films, are used to identify distinct fatigue mechanisms. Microcracking or electrode delamination less than 100 Å is sufficient to explain the high correlation between the dielectric permittivity and remanent polarization during fatigue.

scholarly journals Optimization of piezoelectric MEMS process on Sr and La co-doped PZT thin films

2020 ◽  
Vol 10 (04) ◽  
pp. 2050010
Author(s):  
M. Kathiresan ◽  
Jain Jose ◽  
E. Varadarajan ◽  
R. Ramesh ◽  
V. Natarajan ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Lead Zirconate Titanate ◽  
Etching Rate ◽  
Dry Etching ◽  
Mems Devices ◽  
Pzt Thin Films ◽  
Sensing Applications ◽  
Piezoelectric Mems ◽  
Co Doped

Doped lead–zirconate–titanate (PZT) thin films are preferred for the development of micro–electro–mechanical systems (MEMS)-based acoustic sensors because of their inherent higher dielectric and piezoelectric coefficients. Patterning process is used to develop such MEMS devices which is highly complex even for undoped PZT thin films; therefore, the problem is further cumbersome for doped PZT thin films due to the presence of added dopant elements and their associated chemistry. This paper presents patterning of strontium (Sr) and lanthanum (La) co-doped PZT thin film (PSLZT) deposited on platinized silicon substrate using wet and dry etching processes for fabricating a diaphragm structure with thickness of 15–25[Formula: see text][Formula: see text]m and diameter of 1.4–2[Formula: see text]mm, suitable for acoustic sensing applications. The effects of various etching conditions have been studied and the results are reported. It is found that the dry etching is the most suited process for realizing the piezoelectric MEMS structure due to its higher etching resolution. An appreciable etching rate of 260–270[Formula: see text]nm/min with smooth vertical sidewalls is achieved. The silicon diaphragm with patterned PSLZT thin film is found to retain more than 80% of its dielectric and piezoelectric coefficients and has a resonance of 1.43[Formula: see text]MHz.

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