Microstructural Characterization of Ferroelectric Thin Films for Non-Volatile Memory Applications

1990 ◽  
Vol 200 ◽  
Author(s):  
Sharon A. Myers ◽  
Leo N. Chapin
Keyword(s):  
Thin Films ◽  
Lead Zirconate Titanate ◽  
Pyrochlore Phase ◽  
Microstructural Characterization ◽  
Cmos Technology ◽  
Lead Zirconate ◽  
Ferroelectric Thin Films ◽  
Grain Structure ◽  
Non Volatile Memory ◽  
Memory Applications

ABSTRACTFerroelectric thin films are now being used in conjunction with semiconductor CMOS technology to produce non-volatile IC memory devices. Three film compositions across the lead-zirconate-titanate (PZT) phase diagram were examined by transmission electron microscopy (TEM). The films are produced using organo-metallic sol-gels and sintered using standard semiconductor processing techniques. The grain structure of these thin films differ greatly from bulk ceramic crystals and thin films prepared using other deposition techniques. For two compositions, Pb1.1 (Zr0.75Ti0. 25)O3 and Pb1.1 (Zr0.50Ti0.50)O3, the perovskite structure was found in large rosettes surrounded by the polycrystalline pyrochlore phase. In the Pb1.1(Zr0.25Ti0.75)O3 sample, perovskite grains were found with no evidence of the pyrochlore phase. Ferroelectric domains were imaged in all three samples.

Phase transformations in rapid thermal processed lead zirconate titanate

1995 ◽  
Vol 10 (12) ◽  
pp. 3149-3159 ◽  
Author(s):  
Ellen M. Griswold ◽  
L. Weaver ◽  
M. Sayer ◽  
I.D. Calder
Keyword(s):  
Thin Films ◽  
Lead Zirconate Titanate ◽  
Perovskite Phase ◽  
Sol Gel ◽  
Pyrochlore Phase ◽  
Lead Zirconate ◽  
Grain Structure ◽  
Avrami Model ◽  
Pzt Thin Films ◽  
Zirconate Titanate

The crystallization kinetics of the pyrochlore to perovskite phase transformation in lead zirconate titanate (PZT) thin films have been analyzed using rapid thermal processing (RTP). Sol-gel PZT thin films, fabricated on platinum electrodes, were annealed at 550 °C to 650 °C with hold times ranging from 1 s to 5 min. Glancing angle x-ray diffraction (XRD) was used for depth profiling to identify the location of phases in the films. Transmission electron microscopy (TEM) provided information on grain structure, nucleation, and growth. The phase information was correlated to the ferroelectric and dielectric properties. The perovskite phase nucleated in the pyrochlore phase throughout the film thickness, and at 650 °C the transformation was complete in 15 s. Fast growing (100) PZT nucleated at the platinum and consumed a small-grained matrix until a columnar structure was obtained. A ramp rate of 100 °C/s was sufficiently fast to prevent transformation during heating and allowed the direct application of an Avrami model for transformation kinetics. An activation energy of 610 kJ/mol was determined.

Epitaxial Growth and Electrical Characterization of PBZT Thin Films by RF Magnetron Sputtering Deposition

2007 ◽  
Vol 336-338 ◽  
pp. 173-176
Author(s):  
Hui Qing Fan ◽  
Lai Jun Liu ◽  
Xiu Li Chen ◽  
Jie Zhang ◽  
Wei Wang
Keyword(s):  
Thin Films ◽  
Magnetron Sputtering ◽  
Lead Zirconate Titanate ◽  
Pyrochlore Phase ◽  
Electrical Characterization ◽  
Rf Magnetron Sputtering ◽  
Lead Zirconate ◽  
Sputtering Deposition ◽  
Si Substrates ◽  
Ferroelectric Hysteresis

Barium modified lead zirconate titanate (PBZT) thin films were grown epitaxially on Pt/Ti/SiO2/Si substrates by radio-frequency magnetron sputtering deposition and characterized by X-ray diffraction and scanning electron microscopy. Depending on the growth condition, a wide variation of crystal structure and morphology was evolved in PBZT thin films. The formation of phase structure and pyrochlore phase was strongly dependent on the oxygen partial pressure and re-evaporation of lead from the films during the deposition. Perovskite films were obtained by optimizing the deposition conditions and analyzed by the ferroelectric hysteresis (P~E).

The influence of niobium-doping on lead zirconate titanate ferroelectric thin films

1991 ◽  
Vol 69 (3-4) ◽  
pp. 260-264 ◽  
Author(s):  
E. M. Griswold ◽  
M. Sayer ◽  
D. T. Amm ◽  
I. D. Calder
Keyword(s):  
Thin Films ◽  
Lead Zirconate Titanate ◽  
Ferroelectric Properties ◽  
Lead Zirconate ◽  
Ferroelectric Thin Films ◽  
Crystallographic Structure ◽  
Niobium Content ◽  
Processing Technologies ◽  
Niobium Doping ◽  
Zirconate Titanate

Ferroelectric thin films have recently proven viable for nonvolatile memory applications in semiconductor technology. Current research is focused on the development of processing technologies and deposition on metallized semiconductor substrates. In this study, niobium-doped lead zirconate titanate thin films were prepared by a dc magnetron-sputtering technique using a multielement metal target. Films were deposited on indium tin oxide coated glass and on metallizations on silicon substrates. The crystallographic structure and surface morphology of the films was examined by scanning electron microscopy and X-ray diffraction as a function of processing variables such as sputtering pressure, film thickness, and niobium content. Electrical characterization of the films is discussed in terms of ferroelectric hysteresis and polarization properties. Improved ferroelectric properties are achieved through a densified structure resulting from niobium-doping.

Scaling and disorder analysis of localI–Vcurves from ferroelectric thin films of lead zirconate titanate

2011 ◽  
Vol 22 (25) ◽  
pp. 254031 ◽  
Author(s):  
Peter Maksymovych ◽  
Minghu Pan ◽  
Pu Yu ◽  
Ramamoorthy Ramesh ◽  
Arthur P Baddorf ◽  
...  
Keyword(s):  
Thin Films ◽  
Lead Zirconate Titanate ◽  
Lead Zirconate ◽  
Ferroelectric Thin Films ◽  
Zirconate Titanate

Orientation Dependence of Strontium-doped Lead Zirconate Titanate (PSZT) Thin Films on RF Magnetron Sputtering Conditions

2006 ◽  
Vol 928 ◽  
Author(s):  
Sharath Sriram ◽  
Madhu Bhaskaran ◽  
Anthony Stephen Holland ◽  
Geoffrey K Reeves
Keyword(s):  
Thin Films ◽  
Magnetron Sputtering ◽  
Cooling Rate ◽  
Lead Zirconate Titanate ◽  
Ferroelectric Properties ◽  
Rf Magnetron Sputtering ◽  
Lead Zirconate ◽  
Orientation Dependence ◽  
Grain Structure ◽  
Zirconate Titanate

ABSTRACTStudies on strontium-doped lead zirconate titanate (PSZT) have been reported for its high piezoelectric and ferroelectric properties. For PSZT to exhibit pronounced piezoelectric behaviour it must have a crystalline grain structure (perovskite orientation). This paper is a study of the deposition of PSZT thin films by RF magnetron sputtering and the effect of cooling rate, after deposition at temperatures between 500 °C and 700 °C. X-Ray Diffraction (XRD) results are used to show how a cooling rate of 5 °C/min increases the degree of perovskite orientation in sputtered films, when compared to a cooling rate of 15 °C/min. The absence of significant shifts in the positions of diffraction peak patterns in XRD results are used to demonstrate low stress in the deposited films. Atomic Force Microscope (AFM) imaging is used to show the crystalline nature of the PSZT thin films.

Electrical Properties of Amorphous Thin Films of Ferroelectric Oxides Prepared by Sol-Gel Technique

1993 ◽  
Vol 310 ◽  
Author(s):  
Yuhuan Xu ◽  
Ren Xu ◽  
Chih-Hsing Cheng ◽  
John D. Mackenzie
Keyword(s):  
Thin Films ◽  
Electrical Properties ◽  
Lead Zirconate Titanate ◽  
Sol Gel ◽  
Lead Zirconate ◽  
Ferroelectric Thin Films ◽  
Amorphous Thin Films ◽  
Crystalline Films ◽  
Gel Technique ◽  
Ferroelectric Oxides

AbstractAmorphous thin films of ferroelectric oxides including lead zirconate titanate (PZT), barium titanate (BaTiO3) and lithium niobate (LiNbO3) on several kinds of substrates were prepared by a sol-gel technique. The heat-treatment temperatures for preparation of amorphous thin films were much lower than those for the corresponding crystalline ferroelectric thin films. Electrical properties of these amorphous thin films were measured and compared with those of corresponding crystalline films. These amorphous thin films exhibited ferroelectric-like behavior. A model of the microstructure of these films is proposed.

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