Step Coverage of Pb(ZrTi)O3 Thin Films Grown by Mocvd

1996 ◽  
Vol 433 ◽  
Author(s):  
M. Shimizu ◽  
S. Hyodo ◽  
H. Fujisawa ◽  
H. Niu ◽  
T. Shiosaki
Keyword(s):  
Thin Films ◽  
Aspect Ratio ◽  
Growth Temperature ◽  
Perovskite Phase ◽  
Reaction Pressure ◽  
Step Coverage ◽  
Pzt Films

AbstractStep coverage of PZT grown by MOCVD was influenced by the growth temperature, the reaction pressure and the aspect ratio of the trench. PZT films grown on Si steps at growth temperatures ranging from 500 to 600°C and at reaction pressures ranging from 3 to 10Torr showed a step coverage of 52 to 86%. The step coverage of PZT grown at 600°C and at 5Torr – conditions which were suitable for the growth of perovskite phase – was 75%. The step coverage of Pt on Si and on SiO2 was 20% and 25%, respectively.

Influence of Platinum Bottom Electrodes on the Piezoelectric Performance of PZT Thin Films Hot Sputtered in a High Volume Production Tool

2012 ◽  
Vol 1397 ◽  
Author(s):  
Dirk Kaden ◽  
Hans-Joachim Quenzer ◽  
Martin Kratzer ◽  
Lorenzo Castaldi ◽  
Bernhard Wagner ◽  
...  
Keyword(s):  
Thin Films ◽  
Volume Fraction ◽  
Perovskite Phase ◽  
Annealing Treatment ◽  
High Volume ◽  
Deposition Process ◽  
Pzt Thin Films ◽  
Pzt Films ◽  
High Volume Production ◽  
Volume Production

ABSTRACTIn this work high quality ferroelectric PZT films have been prepared in-situ by hot RF magnetron sputtering. 200 mm wafer were coated with PZT films of 1 μm and 2 μm thickness at sputter rates of 45 nm/min in a high volume production sputtering tool. The films were grown on oxidized Si substrates prepared either with sputtered Ti/TiO2/Pt, sputtered Ti/TiO2/Pt/TiO2 or evaporated Ti/Pt bottom electrodes at substrate holder temperatures in the range from 550 °C to 700 °C. At these temperatures, the material nucleates in the requisite piezoelectric perovskite phase without need of an additional post annealing treatment.The films were investigated with respect to their chemical composition and their crystallographic, piezoelectric and dielectric properties. At an intermediate chuck temperature of 600 °C the PZT thin films were characterized by a minimum volume fraction of secondary nonpiezoelectric phases. A Zr/(Zr+Ti) ratio of 0.53 has been achieved matching the morphotropic phase boundary. By improving the deposition process and poling procedure, a notable high e31,f coefficient of -17.3 C/m2 has been obtained. The corresponding longitudinal piezoelectric constant was determined to have an effective longitudinal piezoelectric coefficient d33,f of 160 pm/V.

Effect of Pb Content on the Transformation of Sputtered PbxZr0.4Ti0.6O3 Thin Film

1993 ◽  
Vol 321 ◽  
Author(s):  
Jae-Hyun Joo ◽  
Deok-Sin Kill ◽  
Seung-Ki Joo
Keyword(s):  
Thin Film ◽  
Crystal Structure ◽  
Thin Films ◽  
Transition Temperature ◽  
Temperature Region ◽  
Transformation Temperature ◽  
Perovskite Phase ◽  
Effective Medium Approximation ◽  
Transformation Kinetics ◽  
Pzt Films

ABSTRACTPZT (PbxZr0.4Ti0.6O3) thin films were prepared by reactive co-sputtering and annealed by RTA (Rapid Thermal Annealing). Transformation kinetics and effect of Pb content on the transformation were intensively studied using EMA (Effective Medium Approximation). It has been found that depending on Pb content as well as RTA temperature, the crystal structure of PZT films changed greatly. It turned out that the transformation temperature for the perovskite phase can be lowered and the width of transition temperature region was reduced by increasing Pb content in the films. Dependence of transformation path on the Pb content has been studied.

A Study on the Selective Nucleations for Formation of Large Single Grains in PZT Thin Films

1999 ◽  
Vol 596 ◽  
Author(s):  
Jang-Sik Lee ◽  
Eung-Chul Park ◽  
Jung-Ho Park ◽  
Byung-Il Lee ◽  
Seung-Ki Joo
Keyword(s):  
Thin Films ◽  
Grain Boundary ◽  
Perovskite Phase ◽  
Breakdown Field ◽  
Pzt Thin Films ◽  
Random Nucleation ◽  
Saturation Polarization ◽  
Pt Electrodes ◽  
Pzt Films ◽  
Pt Films

AbstractSelective nucleation and lateral growing method have been developed for high quality ferroelectric PZT(65/35) thin films using perovskite-phase PZT island seed. The PZT films on PZT seed island were transformed into the perovskite phase at temperatures as low as 540°C, which is 150°C lower than compared to that of PZT thin films deposited on Pt films. The temperature difference enables lateral growth without undesirable random nucleation. Maximum grain sizes of the perovskite-phase PZT films were determined by the annealing temperature. The PZT thin films show a leakage current density of 8×10−8 A/cm2, breakdown field of 1240 kV/cm, saturation polarization of 42 μC/cm2, and remanent polarization of 30 μC/cm2, whose values were maintained up to 2×1011 cycles. In this study, we show that when there was no grain boundary in the area measured, degradation such as fatigue and retention was not observed even with Pt electrodes. So the main source of degradation is the grain boundary in the PZT thin films.

Effect of Microwave Irradiation on Rapid Crystallization of Ferroelectric Lead Zirconate Titanate Thin Films

2013 ◽  
Vol 750 ◽  
pp. 220-223
Author(s):  
Xian Wei Wang ◽  
Zhan Jie Wang ◽  
Yan Na Chen ◽  
Yu Qing Zhang ◽  
Zhi Dong Zhang
Keyword(s):  
Thin Films ◽  
Microwave Irradiation ◽  
Lead Zirconate Titanate ◽  
Perovskite Phase ◽  
Lead Zirconate ◽  
Process Time ◽  
Rapid Crystallization ◽  
Furnace Process ◽  
Conventional Furnace ◽  
Pzt Films

Ferroelectric Pb(Zr0.52Ti0.48)O3 (PZT) thin films rapidly crystallized by microwave irradiation were compared with those obtained by conventional furnace process. The PZT films under microwave irradiation at 650 °C for 60 s were crystallized well in to the perovskite phase, and showed butter electrical properties than those crystallized by conventional furnace annealing at 650 °C for 30 min. It is clear that microwave irradiation is effective for obtaining well-crystallized PZT films with good properties in a short process time.

Issues in the Flexible Integration of Sputter-Deposited PZT Thin Films with Polysilicon and Ti/Pt Electrode Layers for Use as Sensors and Actuators in Microelectromechanical Systems (MEMS)

2000 ◽  
Vol 657 ◽  
Author(s):  
C.F. Knollenberg ◽  
T.D. Sands ◽  
A.S. Nickles ◽  
R.M. White
Keyword(s):  
Thin Films ◽  
Lead Zirconate Titanate ◽  
Microelectromechanical Systems ◽  
Perovskite Phase ◽  
Ferroelectric Properties ◽  
Pt Electrode ◽  
Electrode Layer ◽  
Pzt Thin Films ◽  
Pzt Films ◽  
Sputter Deposited

ABSTRACTSputter-deposited piezoelectric lead zirconate titanate (PZT) thin films with Ti/Pt and polysilicon electrode layers are being investigated for use in Microelectromechanical Systems (MEMS). Existing research shows the nucleation of the perovskite phase of the PZT is linked to the lattice spacing of the underlying Pt electrode and/or seed layers, and is key in obtaining PZT layers with good piezoelectric/ferroelectric properties. Our research with piezoelectric PZT films on Ti/Pt electrode layers aims at employing these films to generate and receive acoustic waves in flexural plate wave devices (FPWs). Our experiments indicate the formation of a random polycrystalline perovskite phase is linked to the emergence of oriented <100> Pt grains within the dominant <111>-oriented crystal structure during rapid thermal annealing in an oxygen environment. Pt films annealed in nitrogen, in contrast, retained their <111> preferential orientation without the formation of Pt <100> grains. PZT films deposited on these electrodes and annealed in nitrogen were strongly oriented in the <111> direction, but exhibited lossy ferroelectric behavior and were prone to delamination. We are also investigating the feasibility of using doped polysilicon electrode layers with PZT thin films. The multiple layers used with the Pt electrode (Pt, Ti, and SiO2 adhesion layer) have significant interactions with one another, and replacing these layers with a single electrode layer should alleviate these complications. A low-temperature PZT deposition process (300°C) and short annealing cycles (30 sec.), coupled with a TiO2 barrier/seed layer should prevent interdiffusion and reactions between the polysilicon and PZT layers. Our experiments show that PZT films deposited and annealed on doped polysilicon layers develop a random polycrystalline perovskite phase, but are subject to tensile cracking. The use of polysilicon as an electrode layer should also facilitate the integration of piezoelectric PZT layers with polysilicon surface micromachined structures using SiGe sacrificial layers.

Laser-Assisted Low Temperature Processing of PZT Thin Films

1997 ◽  
Vol 493 ◽  
Author(s):  
Yongfei Zhu ◽  
Jinsong Zhu ◽  
Y. J. Song ◽  
S. B. Desu
Keyword(s):  
Thin Films ◽  
Low Temperatures ◽  
Laser Annealing ◽  
Perovskite Phase ◽  
Ferroelectric Properties ◽  
Processing Temperature ◽  
Pzt Thin Films ◽  
Step Process ◽  
Pzt Films ◽  
One Step

ABSTRACTA novel method for lowering processing temperature of ferroelectric Pb(Zr1−xTix)O3 (PZT) thin films was developed utilizing a laser-assisted two-step process. In the first step, perovskite phase was initiated in the PZT films by subjecting the films to a fornace anneal at low temperatures in the range of 470 °C to 550 °C depending on the Zr/Ti ratio. Later, the films were laser-annealed (using krF excimer laser) at room temperature to grow the perovskite phase, and to improve microstructure and ferroelectric properties. It was found that this two-step process was very effective in producing excellent quality ferroelectric PZT films at low temperatures. It should be noted that although laser annealing of amorphous and/or pyrochlore films directly (one-step process) produces perovskite phase, the ferroelectric properties of these films, irrespective of the composition, were rather unattractive. Some possible reasons for the ineffectiveness of the one-step process were discussed.

Pzt Thin Films on a Lead Titanate Interlayer Prepared by rf Magnetron Sputering

1993 ◽  
Vol 310 ◽  
Author(s):  
P. H. Ansari ◽  
A. Safari
Keyword(s):  
Thin Films ◽  
Lead Zirconate Titanate ◽  
Lead Titanate ◽  
Silicon Oxide ◽  
Perovskite Phase ◽  
Dissipation Factor ◽  
Lead Zirconate ◽  
Si Substrate ◽  
Pzt Thin Films ◽  
Pzt Films

AbstractFerroelectric lead zirconate titanate (PZT) films with a composition near the morphotropic phase boundary have been deposited by if magnetron sputtering on a Si substrate coated with silicon oxide, titanium, and platinum (Si/SiO2/Ti/Pt). Substrate temperature and oxygen partial pressure were changed during deposition to prepare films with controlled stoichiometry and perovskite structure. The effects of lead titanate (PT) as a buffer layer were investigated. Thin films of PT/PZT have a dielectric constant of 800 with a dissipation factor of 0.04 at 1 kHz. The remnant polarization of 8μC/cm2 and the coercive field of 50 kV/cm were measured. The effect of processing on the formation of perovskite phase and the electrical properties will be discussed.

Growth and Characterization of Ferroelectric Pb(Zr,Ti)OM3 Thin Films by Mocvd Using A 6 Inch Single Wafer Cvd System

1993 ◽  
Vol 310 ◽  
Author(s):  
Masaru Shimizu ◽  
Masashi Fujimoto ◽  
Takuma Katayama ◽  
Tadashi Shiosaki ◽  
Kenichi Nakaya ◽  
...  
Keyword(s):  
Thin Films ◽  
Growth Process ◽  
Perovskite Phase ◽  
Large Area ◽  
Entire Area ◽  
System A ◽  
Pzt Films ◽  
Step Growth ◽  
Si Wafer

AbstractFerroelectric Pb(Zr,Ti)O3(PZT) films with a perovskite phase were successfully grown by MOCVD using a 6 inch wafer CVD system. A two step growth process was proposed to obtain perovskite PZT films at high gas supplying ratios of [Zr]/([Zr]+[Ti]). The electrical properties of the PZT films obtained were measured. Large area growths of PZT films were carried out and the uniform films could be grown on the entire area of a 6 inch Si wafer. It was also found that the step coverage characteristic of the films grown by MOCVD was good.

Large Area PbZr1−xTixO3 (PZT) Thin Films Deposited by MOCVD Processes

1997 ◽  
Vol 493 ◽  
Author(s):  
Tingkai Li ◽  
Elliot Hartford ◽  
Pete Zawadzki ◽  
Richard A. Stall
Keyword(s):  
Thin Films ◽  
Perovskite Phase ◽  
Process Conditions ◽  
Large Area ◽  
Homogeneous Microstructure ◽  
Pzt Thin Films ◽  
Si Substrates ◽  
Pt Electrodes ◽  
Pzt Films ◽  
Ray Patterns

ABSTRACTAn advanced oxide MOCVD tool and processes have been developed to deposit large area PbZr1−xTixO3 (PZT) thin films on 6” Si and Pt/Ti/SiO2/Si substrates. The experimental results show the advanced oxide MOCVD tool can achieve the growth of PZT thin films with thickness uniformity of 2% and composition uniformity better that 3% on both 6” Si and Pt/Ti/SiO,/Si wafers at high deposition rates. X-ray patterns showed a single PZT perovskite phase, and AFM showed homogeneous microstructure and low surface roughness. Typically, 300 nm thick PZT films with a grain size about 0.3 μm have Pr greater than 20 - 30 μC/cm2 at 5V, a dielectric constant around 1000, low coercive field (Ec 50 - 70 kV/cm), and fatigue rate (the normalized polarization is about 0.6 after 1010 cycles at 5 V), and leakage current of 2 - 6×lO−7 A/cm2 at 150 kV/cm and room temperature on Pt electrodes. In addition, the effects of reactor design and process conditions on the thickness and composition uniformity, as well as the m i ero structure and properties were also investigated.

Effect of Pb Excess Content on Microstructure and Electrical Properties of Sol Gel Derived PZT Thin Films

1999 ◽  
Vol 596 ◽  
Author(s):  
Zhan-jie Wang ◽  
Ryutaro Maeda ◽  
Kaoru Kikuchi
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Lead Zirconate Titanate ◽  
Perovskite Phase ◽  
Ferroelectric Properties ◽  
Sol Gel ◽  
Lead Zirconate ◽  
Pzt Thin Films ◽  
Starting Solution ◽  
Pzt Films

AbstractLead zirconate titanate (PZT) thin films were fabricated by a three-step heat-treatment process which involves the addition of -10, 0 and 10 mol% excess Pb to the starting solution and spin coating onto Pt/Ti/SiO2/Si substrates. Crystalline phases as well as preferred orientations in PZT films were investigated by X-ray diffraction analysis (XRD). The microstructure and composition of the films were studied by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and electron probe microanalysis (EPMA), respectively. The well-crystallized perovskite phase and the (100) preferred orientation were obtained by adding 10% excess Pb to the starting solution. It was found that PZT films to which 10% excess Pb was added had better electric properties. The remanent polarization and the coercive field of this film were 34.8 μC/cm2 and 41.7 kV/cm, while the dielectric constant and loss values measured at 1 kHz were approximately 1600 and 0.04, respectively. Dielectric and ferroelectric properties were correlated to the microstructure of the films.

Sign in / Sign up

Export Citation Format

Share Document