Characterization of Highly Textured PZT Thin Films Grown on LaNiO3 Coated Si Substrates by MOCVD

1997 ◽  
Vol 493 ◽  
Author(s):  
C. H. Lin ◽  
B. M. Yen ◽  
Haydn Chen ◽  
T. B. Wu ◽  
H. C. Kuo ◽  
...  

ABSTRACTHighly textured PbZrxTi1−xO3 (PZT) thin films with x= 0-0.6 were grown on LaNiO3 coated Si substrates at 600 °C by metal-organic chemical vapor deposition (MOCVD). The preferred crystalline orientation of PZT thin films with various Zr concentration were characterized by X-ray diffraction (XRD). Microstructures were studied by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The dielectric constants, hysteresis and fatigue behavior of these thin films were also measured. The relationship between growth rate and the preferential orientation is discussed. Furthermore, the dependence of the electrical properties on Zr concentration and preferential orientation is demonstrated.

1998 ◽  
Vol 541 ◽  
Author(s):  
Nan Chen ◽  
G. R. Bai ◽  
O. Auciello ◽  
R. E. Koritala ◽  
M. T. Lanagan

AbstractSingle-phase polycrystalline PbZrO3 (PZ) thin films, 3000-6000 A thick, have been grown by metal-organic chemical vapor deposition (MOCVD) on (111)Pt/Ti/SiO2/Si substrates at ≍525°C. X-ray diffraction analysis indicated that the PZ films grown on (111)Pt/Ti/SiO2/Si (Pt/Tgi/Si) showed preferred pseudocubic (110) orientation. In contrast, PZ films grown on 150 A thick PbTiO3 (PT) template layers exhibited a pseudocubic (100) preferred orientation, and PZ films deposited on TiO2 template layers consisted of randomly oriented grains. The PZ films grown on Pt/Ti/Si with or without templates exhibited dielectric constants of 120-200 and loss tangents of 0.01-0.0. The PZ films with (110) orientation exhibited an electric-field-inducedtransformation from the antiferroelectric phase to the ferroelectric phase with a polarization of ≍34 µC/cm2, and the energy that was stored during switching was 7.1 J/cm3. The field needed to excite the ferroelectric state and that needed to revert to the antiferroelectric state were 50 and 250 kV/cm, respectively. Relationships between the MOCVD processing and the film microstructure and properties are discussed.


2006 ◽  
Vol 45 ◽  
pp. 1194-1199
Author(s):  
Raffaella Lo Nigro ◽  
Roberta G. Toro ◽  
Graziella Malandrino ◽  
Ignazio L. Fragalà

CaCu3Ti4O12 (CCTO) thin films have been successfully deposited by Metal Organic Chemical Vapor Deposition (MOCVD) technique. A novel approach based on a molten multicomponent precursor source has been applied. The molten mixture consists of the Ca(hfa)2•tetraglyme, Ti(tmhd)2(O-iPr)2, and Cu(tmhd)2 [Hhfa= 1,1,1,5,5,5-hexafluoro-2,4- pentanedione; tetraglyme= 2,5,8,11,14-pentaoxapentadecane; Htmhd= 2,2,6,6-tetramethyl-3,5- heptandione; O-iPr= iso-propoxide] precursors. Film complete structural and morphological characterizations have been carried out using several techniques [X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM)].


1998 ◽  
Vol 541 ◽  
Author(s):  
C. H. Lin ◽  
H. C. Kuo ◽  
G. E. Stillman ◽  
Haydn Chen

AbstractHighly (100) textured pseudo-cubic Pb(ScTa)1−xTixO3 (x=0-0.3) (PSTT) thin films were grown by metal-organic chemical vapor deposition (MOCVD) on LaNiO3 (LNO) electrode buffered Si substrates at 650 °C. The microstructure and chemical uniformity were studied using X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM) and nanoprobe X-ray energy dispersive spectroscopy (EDS). The temperature dependence of dielectric properties and P-E behavior were measured. A shift of Curie temperature of these PST-based thin films due to Ti addition was demonstrated, Furthermore, the pyroelectric properties of these thin films were estimated.


2019 ◽  
Vol 25 (6) ◽  
pp. 1383-1393
Author(s):  
Sabyasachi Saha ◽  
Deepak Kumar ◽  
Chandan K. Sharma ◽  
Vikash K. Singh ◽  
Samartha Channagiri ◽  
...  

AbstractGaN films have been grown on SiC substrates with an AlN nucleation layer by using a metal organic chemical vapor deposition technique. Micro-cracking of the GaN films has been observed in some of the grown samples. In order to investigate the micro-cracking and microstructure, the samples have been studied using various characterization techniques such as optical microscopy, atomic force microscopy, Raman spectroscopy, scanning electron microscopy and transmission electron microscopy (TEM). The surface morphology of the AlN nucleation layer is related to the stress evolution in subsequent overgrown GaN epilayers. It is determined via TEM evidence that, if the AlN nucleation layer has a rough surface morphology, this leads to tensile stresses in the GaN films, which finally results in cracking. Raman spectroscopy results also suggest this, by showing the existence of considerable tensile residual stress in the AlN nucleation layer. Based on these various observations and results, conclusions or propositions relating to the microstructure are presented.


2002 ◽  
Vol 745 ◽  
Author(s):  
Patrick S. Lysaght ◽  
Brendan Foran ◽  
Gennadi Bersuker ◽  
Larry Larson ◽  
Robert W. Murto ◽  
...  

ABSTRACTEvaluation of physically thicker gate insulator materials with significantly higher dielectric constants (k = 10 – 25) as potential replacements for silicon dioxide, SiO2 (k = 3.9), and silicon oxynitride continues to be a focus of the semiconductor industry. The challenge is to provide a film with lower leakage current and with capacitance equivalent to < 1.0 nm SiO2 [1–4]. One such candidate material; metal-organic chemical vapor deposited (MOCVD) hafnium silicate, has been physically characterized by high resolution transmission electron microscopy (HRTEM) in plan view, as a blanket, uncapped film and high angle annular dark field scanning transmission electron microscopy (HAADF-STEM) in cross section following integration into capacitors and complementary metal oxide semiconductor (CMOS) transistors. Changes in the material microstructure associated with phase segregation and crystallization as a function of Hf silicate composition and rapid thermal anneal (RTA) temperature have been observed and a discussion of the segregation mechanisms is presented [5–8]. Also, various methods of incorporating nitrogen into bulk hafnium silicate films have been investigated and resultant transistor electrical performance data has been correlated with physical characterization for NH3 post deposition anneal (PDA) treatments at various temperatures.


Nanomaterials ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 2450
Author(s):  
Oumaima Abouzaid ◽  
Hussein Mehdi ◽  
Mickael Martin ◽  
Jérémy Moeyaert ◽  
Bassem Salem ◽  
...  

The epitaxy of III-V semiconductors on silicon substrates remains challenging because of lattice parameter and material polarity differences. In this work, we report on the Metal Organic Chemical Vapor Deposition (MOCVD) and characterization of InAs/GaAs Quantum Dots (QDs) epitaxially grown on quasi-nominal 300 mm Ge/Si(001) and GaAs(001) substrates. QD properties were studied by Atomic Force Microscopy (AFM) and Photoluminescence (PL) spectroscopy. A wafer level µPL mapping of the entire 300 mm Ge/Si substrate shows the homogeneity of the three-stacked InAs QDs emitting at 1.30 ± 0.04 µm at room temperature. The correlation between PL spectroscopy and numerical modeling revealed, in accordance with transmission electron microscopy images, that buried QDs had a truncated pyramidal shape with base sides and heights around 29 and 4 nm, respectively. InAs QDs on Ge/Si substrate had the same shape as QDs on GaAs substrates, with a slightly increased size and reduced luminescence intensity. Our results suggest that 1.3 μm emitting InAs QDs quantum dots can be successfully grown on CMOS compatible Ge/Si substrates.


1988 ◽  
Vol 144 ◽  
Author(s):  
P. Grodzinski ◽  
J.H. Mazur ◽  
A. Nouhi ◽  
R.J. Stirn ◽  
R. Sudharsananu

ABSTRACTElectron diffraction and high resolution electron microscopy (HREM) have been used to investigate the origin of multiple orientation-relationships and defect structure of CdTe thin films grown on (100) GaAs and Si substrates by metal- organic chemical vapor deposition (MOCVD). It has been determined that growth at 370°C with pre-exposure of the GaAs surface to Te following oxide desorption treatment at 600°C resulted in non-parallel epitaxy ((111)CdTe // (100)GaAs), while growth at 300°C following oxide desorption at 500°C with no exposure to Te resulted in parallel epitaxy ((100)CdTe // (100)GaAs). Both epitaxial orientation-relationships were observed on the same substrate for growth at 300°C temperature after 600°C oxide desorption treatment, but with no pre-exposure of the GaAs surface to Te. Preliminary results of growth of CdTe on Si are also reported.


1989 ◽  
Vol 162 ◽  
Author(s):  
H. A. Hoff ◽  
A. A. Morrish ◽  
W. A. Carrington ◽  
J. E. Butler ◽  
B. B. Rath

ABSTRACTDiamond thin films have been synthesized at low pressures by chemical vapor deposition (CVD) and, recently, at ambient atmosphere with an oxygen-acetylene welding torch. By the application of appropriate thermal or mechanical stresses to the substrate, the diamond films can be delaminated. The delaminated films which are only a few microns thick have been fractured by manual bending. Scanning electron microscopy (SEM) examination of fractured CVD diamond films shows the presence of primarily intragranular fracture attesting to the inherent strength of the films. Using transmission electron microscopy (TEM), twinning and stacking faults are seen within the crystallites of the films along the fracture surfaces. By combining SEM and TEM examination, the relative degree of intragranular fracture found in films synthesized by both CVD and oxygen-acetylene torch has been investigated. Possible mechanisms for the intragranular fracture and the relative strength of such films are discussed.


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