Effects of Annealings on Pt/TiN/Ti Interfacial Reactions

1994 ◽  
Vol 361 ◽  
Author(s):  
F. Varniere ◽  
B. Eakim ◽  
B. Agius ◽  
R. Bisaro ◽  
J. Olivier ◽  
...  

ABSTRACTThe selection of a suitable electrode and barrier layer is important in the integration of lead zirconate titanate (PZT) into memory circuits. Processing at elevated temperatures of up to 800°C can give rise to diffusion processes and therefore to formation of poor quality layers.In this paper we used Rutherford Backscattering Spectrometry (RBS), Auger Electron Spectrometry (AES), and X-ray Diffraction (XRD) to study the effects of annealings on the interdiffusion of Pt/TiN/Ti trilayers deposited on BPSG/Si substrates. The wafers were annealed in Ar, N2 or O2 ambients with temperatures ranging from 550 to 700°C for 60 min, 30 min or 30 sec. Drastic changes occur when the as deposited Pt/TiN/Ti layers on BPSG/Si structures are exposed to classical heat treatment: oxidation induces diffusion of Ti into Pt and oxidation of Ti is also observed. Regardeless of annealing proceedure used, significant improvement in the interdiffusion of Pt, Ti and O have been achieved when the TiN/Ti/BPSG/Si structure was heated up to 450°C in vacuum. Platinum films deposited on such a structure seem to be a promising barrier layer for PZT film elements as there was no indication of Pb diffusion into the underlying layers and furthermore the desired crystal structure was obtained.

1991 ◽  
Vol 243 ◽  
Author(s):  
Rainer Bruchhaus ◽  
Dana Pitzer ◽  
Oliver Eibl ◽  
Uwe Scheithauer ◽  
Wolfgang Hoesler

AbstractThe deposition of the bottom electrode plays a key role in the fabrication of ferroelectric capacitors. Processing at elevated temperatures of up to 800°C can give rise to diffusion processes and thereof formation of harmful dielectric layers.In this paper we used Rutherford backscattering spectrometry (RBS), Auger electron spectrometry (AES) and transmission electron microscopy (TEM) to study Pt/Ti/SiO2/Si substrates with various thicknesses of the Ti and Pt layers. During heating up to about 450°C in vacuum the initial layer sequence remains unchanged. However, drastic changes occur when the electrodes are exposed to Ar/O2 atmosphere during heat treatment. Oxidation induced diffusion of Ti into Pt and oxidation of Ti were observed. A Pt electrode with a 100 nm thick Ti adhesion layer proved to be suitable for the "in-situ" deposition of PZT films.


1999 ◽  
Vol 14 (2) ◽  
pp. 494-499 ◽  
Author(s):  
S. Arscott ◽  
R. E. Miles ◽  
J. D. Kennedy ◽  
S. J. Milne

0.53Ti0.47)O3 have been prepared on platinized GaAs (Pt–GaAs) substrates using a new 1,1,1-tris(hydroxymethyl)ethane (THOME) based sol-gel technique. Rapid thermal processing (RTP) techniques were used to decompose the sol-gel layer to PZT in an effort to avoid problems of GayAs outdiffusion into the PZT. A crystalline PZT film was produced by firing the sol-gel coatings at 600 or 650 ° for a dwell time of 1 s using RTP. A single deposition of the precursor sol resulted in a 0.4 μm thick PZT film. X-ray diffraction measurements revealed that the films possessed a high degree of (111) preferred orientation. Measured average values of remanent polarization (Pr ) and coercive field (Ec) for the film annealed at 650 ° for 1 s were 24 μC/cm2 and 32 kV/cm, respectively, together with a low frequency dielectric constant and loss tangent at 1 kHz of 950 and 0.02. These values are comparable to those obtainable on platinized silicon (Pt–Si) substrates using conventional sol-gel methods, and are an improvement on PZT thin films prepared on platinized GaAs using an earlier sol-gel route based on 1,3-propanediol.


2005 ◽  
Vol 20 (4) ◽  
pp. 882-888 ◽  
Author(s):  
Gun-Tae Park ◽  
Chee-Sung Park ◽  
Jong-Jin Choi ◽  
Hyoun-Ee Kim

Highly (100)- and (111)-oriented lead zirconate titanate (PZT) films with a thickness of 350 nm were deposited on platinized Si substrates through a single spinning of a PZT sol containing polyvinylpyrrolidone (PVP) as an additive. The crystallographic orientation of the film was strongly influenced by pyrolysis conditions after spin coating. When the spin-coated sol was pyrolyzed at temperatures above 320 °C for relatively long periods of time (>5 min), (111)-oriented film was formed after annealing at 700 °C for 10 min. On the other hand, when the same sol was pyrolyzed at 320 °C for short periods of time (<5 min), the film was strongly oriented to the (100) direction after annealing. Organic residues derived from PVP decomposition acted as nucleation sites for the (100) oriented grains during annealing after the pyrolysis. The effective d33 of the (100)-oriented PZT film (100 pC/N) was much higher than that of the (111)-oriented film (62 pC/N) with the same thickness.


2004 ◽  
Vol 830 ◽  
Author(s):  
Hiroshi Nakaki ◽  
Hiroshi Uchida ◽  
Shoji Okamoto ◽  
Shintaro Yokoyama ◽  
Hiroshi Funakubo ◽  
...  

ABSTRACTRare-earth-substituted tetragonal lead zirconate titanate thin films were synthesized for improving the ferroelectric property of conventional lead zirconate titanate. Thin films of Pb1.00REx (Zr0.40Ti0.60)1-(3x /4)O3 (x = 0.02, RE = Y, Dy, Er and Yb) were deposited on (111)Pt/Ti/SiO2/(100)Si substrates by a chemical solution deposition (CSD). B-site substitution using rare-earth cations described above enhanced the crystal anisotropy, i.e., ratio of PZT lattice parameters c/a. Remanent polarization (Pr) of PZT film was enhanced by Y3+-, Dy3+- and Er3+-substitution from 20 μC/cm2 up to 26, 25 and 26 μC/cm2 respectively, while ion substitution using Yb3+ degraded the Pr value down to 16 μC/cm2. These films had similar coercive fields (Ec) of around 100 kV/cm. Improving the ferroelectric property of PZT film by rare-earth-substitution would be ascribed to the enhancement of the crystal anisotropy. We concluded that ion substitution using some rare-earth cations, such as Y3+, Dy3+ or Er3+, is one of promising technique for improving the ferroelectric property of PZT film.


2014 ◽  
Vol 609-610 ◽  
pp. 1331-1335
Author(s):  
Jun Jie Chen ◽  
Ying Liu ◽  
Jian Qiang Ma ◽  
Ji Cong Deng ◽  
Bao Qing Li ◽  
...  

This paper demonstrates that the deformation of the piezoelectric deformable mirror (DM) is proportional to the transverse piezoelectric coefficient of the lead zirconate titanate (PZT) by the theoretical analysis. The optimal polarization conditions were obtained by experiments to optimize the performance of the DM. After the optimal polarization, the transverse piezoelectric coefficient of the PZT film increases from 350 pm/V to 431 pm/V, which will improve the deformation of the DM.


1994 ◽  
Vol 360 ◽  
Author(s):  
D.A. Barrow ◽  
T.E. Petroff ◽  
M. Sayer

AbstractLead zirconate titanate (PZT) films of up to 60 μm in thickness have been fabricated on a wide variety of substrates using a new sol gel process. The dielectric properties (∈ = 900), ferroelectric (Ec = 16 kV/cm and Pr = 35 μC/cm 2) and piezoelectric properties are comparable to bulk values. The characteristic Curie point of these films is at 420 °C. Piezoelectric actuators have been developed by depositing thick PZT films on both planar and coaxial substrates. Stainless steel cantilevers and optical fibres coated with a PZT film exhibit flexure mode resonant vibrations observable with the naked eye. A low frequency in-line fibre optic modulator has been developed using a PZT coated optical fibre. The high frequency resonance of a 60 μm film on a aluminum substrate has been observed.


2013 ◽  
Vol 582 ◽  
pp. 15-18
Author(s):  
Y. Minemura ◽  
Y. Kondoh ◽  
H. Funakubo ◽  
Hiroshi Uchida

One-axis-oriented Pb (Zr,Ti)O3(PZT) films were fabricated using a chemical solution deposition technique on (111)Pt/TiO2/(100)Si and Inconel625 substrates buffered by nanosheet Ca2Nb3O10(ns-CN). The (001)-oriented PZT crystals (Zr/Ti=0.40:0.60, tetragonal) were preferentially grown on (001)ns-CN/Inconel625, whereas the PZT crystals deposited on (001)ns-CN/(111)Pt/ TiO2/(100)Si exhibited preferential PZT(100) orientation. The resulting PZT film on (001)ns-CN/Inconel625 indicated remanent polarization of approximately 59 μC/cm2, which was significantly larger than that on (001)ns-CN/(111)Pt/TiO2/(100)Si.


2020 ◽  
Vol 28 ◽  
pp. 65-70 ◽  
Author(s):  
Victor V. Petrov ◽  
Yuriy N. Varzarev ◽  
Anton S. Kamentsev ◽  
Andrey A. Rozhko ◽  
Oksana A. Pakhomova

In this paper, we consider the technological features of the formation of thin ferroelectric films of lead zirconate titanate (PZT) by the method of plasma high-frequency reactive sputtering. The crystal structure, morphology and elemental composition of films deposited on silicon and oxidized silicon substrates are investigated. It is shown that the obtained PZT films have a perovskite structure and are polycrystalline with a predominant crystallite growth in the (110) direction. An automated test bench has been designed and manufactured for measuring the electrophysical parameters of ferroelectric films. The measured CV characteristics of the Ni/PZT/Si structure show the hysteresis caused by the polarization of the PZT film. It is noted that the asymmetry of the dependence of the spontaneous polarization on the applied voltage can be caused by the presence of surface states at the PZT/Si interface.


2006 ◽  
Vol 320 ◽  
pp. 49-52
Author(s):  
Hiroshi Uchida ◽  
Hiroshi Nakaki ◽  
Hiroshi Funakubo ◽  
Seiichiro Koda

The electrical properties of perovskite-based ferroelectric films were improved by ion modification using rare-earth cations. Thin films of rare-earth-modified lead zirconate titanate [Pb(Zr,Ti)O3] were fabricated on (111)Pt/Ti/SiO2/(100)Si substrates by a chemical solution deposition technique. The substitution of volatile cations in the simple-perovskite oxides, such as Pb2+ in Pb(Zr,Ti)O3 films, enhanced the insulating properties of the film. The crystal anisotropy of the Pb(Zr,Ti)O3 film could be controlled by varying the species and the amount of replacing cations to enhance the spontaneous polarization. Thus, ion modification using Dy3+ cation could enhance the remanent polarization of Pb(Zr,Ti)O3 film consequently.


2002 ◽  
Vol 741 ◽  
Author(s):  
M.S. Kennedy ◽  
D.F. Bahr ◽  
C.D. Richards ◽  
R.F. Richards

ABSTRACTFlexing piezoelectric membranes can be used to convert mechanical energy to electrical energy. The overall deflection of individual membranes is impacted by the residual stress in the system. Membranes comprised of silicon dioxide, Ti/Pt, lead- zirconate- titanate (PZT), and TiW/Au layers deposited on a micromachined boron doped silicon wafer were examined for both morphology and residual stress. By characterizing the membrane residual stress induced during processing with x-ray diffraction, wafer curvature, and bulge testing and identifying methods to reduce stress, the membrane performance and reliability can be optimized. For Zr:Ti ratios of 52:48, the residual stress in the PZT was 350 MPa tensile, with an overall effective stress in the composite membrane of 150 MPa. A reduction of stress was accomplished by changing the PZT chemistry to 40:60 Zr:Ti in the PZT to obtain a stress in the PZT of 160 MPa tensile and an overall effective membrane stress of 100 MPa. The crystallization of the 52:48 PZT film at 700 °C causes a 28% reduction in the thickness of the film.


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