Author: Prasad Alluri
Publisher:
ISBN:
Category : Dielectrics
Languages : en
Pages : 404
Book Description
Chemical Vapor Deposition of Barium Strontium Titanate Films and Effects of Interfaces on Electrical Behavior
Author: Prasad Alluri
Publisher:
ISBN:
Category : Dielectrics
Languages : en
Pages : 404
Book Description
Publisher:
ISBN:
Category : Dielectrics
Languages : en
Pages : 404
Book Description
Electrical and Optical Properties of Barium Strontium Titanate Thin Films Prepared by Metalorganic Chemical Vapor Deposition
Author: Stephen R. Gilbert
Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
American Doctoral Dissertations
Author:
Publisher:
ISBN:
Category : Dissertation abstracts
Languages : en
Pages : 776
Book Description
Publisher:
ISBN:
Category : Dissertation abstracts
Languages : en
Pages : 776
Book Description
Chemical Vapor Deposition
Author: Jong-Hee Park
Publisher: ASM International
ISBN: 161503224X
Category : Technology & Engineering
Languages : en
Pages : 477
Book Description
Publisher: ASM International
ISBN: 161503224X
Category : Technology & Engineering
Languages : en
Pages : 477
Book Description
Electrical Properties of Vacuum Deposited Barium Titanate on Single Crystal Gold and Platinum Substrates
Author: Alfred John Wunschel
Publisher:
ISBN:
Category :
Languages : en
Pages : 112
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages : 112
Book Description
Microstructure and Nonstoichiometry of Barium Strontium Titanate Thin Films for Dram Applications
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 9
Book Description
In this paper we investigate the microstructural accommodation of nonstoichiometry in (Ba(subscript x)Sr{sub 1-x}Ti{sub 1+y}O{sub 3+z}) thin films grown by chemical vapor deposition. Films with three different (Ba+Sr)/Ti ratios of 49/51 (y=0.04 in the notation of the formula above), of 48/52 (y=0.08) and of 46.5/53.5 (y=O.15), were studied. High-resolution electron microscopy is used to study the microstructure of the BST films. High-spatial resolution electron energy-loss spectroscopy (EELS) is used to reveal changes in chemistry and local atomic environment both at grain boundaries and within grains as a function of titanium excess. We find an amorphous phase at the grain boundaries and grain boundary segregation of excess titanium in the samples with y=0.15. In addition, EELS is also used to show that excess titanium is being partially accommodated in the grain interior. Implications for the film electrical and dielectric properties are outlined.
Publisher:
ISBN:
Category :
Languages : en
Pages : 9
Book Description
In this paper we investigate the microstructural accommodation of nonstoichiometry in (Ba(subscript x)Sr{sub 1-x}Ti{sub 1+y}O{sub 3+z}) thin films grown by chemical vapor deposition. Films with three different (Ba+Sr)/Ti ratios of 49/51 (y=0.04 in the notation of the formula above), of 48/52 (y=0.08) and of 46.5/53.5 (y=O.15), were studied. High-resolution electron microscopy is used to study the microstructure of the BST films. High-spatial resolution electron energy-loss spectroscopy (EELS) is used to reveal changes in chemistry and local atomic environment both at grain boundaries and within grains as a function of titanium excess. We find an amorphous phase at the grain boundaries and grain boundary segregation of excess titanium in the samples with y=0.15. In addition, EELS is also used to show that excess titanium is being partially accommodated in the grain interior. Implications for the film electrical and dielectric properties are outlined.
Barium Strontium Titanate Films for Tunable Microwave and Acoustic Wave Applications
Author: Venkataramanan Gurumurthy
Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
ABSTRACT: The composition-dependent Curie temperature and bias-dependant dielectric permittivity of Barium Strontium Titanate (BST) makes it very attractive for tunable application in the RF/Microwave regime. In this research work, the performance of BST varactors fabricated on the conventional Pt/Ti/SiO2/Si bottom electrode stack were compared with those fabricated using chemical vapor deposited Nanocrystalline Diamond (NCD) as the diffusion barrier layer instead of SiO2. The varactors fabricated on NCD films displayed much better symmetry in capacitance-voltage behavior and better overall quality factors than varactors fabricated on SiO2. The improvement in performance can be attributed to existence of stable interfaces in the devices fabricated on NCD which reduced the bottom electrode losses at high frequencies. The SiO2 based BST varactors on the other hand displayed better reliability and breakdown fields. The main purpose of this research work is to develop a robust Metal Insulator Metal (MIM) structure to achieve better all round performance of BST varactors. In the second part of this research work, the prospect of developing diamond based layered Surface Acoustic Wave (SAW) devices using Ba0.8Sr0.2TiO3 as the piezoelectric layer is investigated. Structural characterization of BST thin films deposited on Si/NCD/Pt and Si/SiO2/Ti/Pt stack were performed using X-Ray Diffraction (XRD) and Atomic Force Microscopy (AFM). Cross-sectional studies on the two stacks were performed using Scanning Electron Microscopy (SEM). X-Ray Mapping (XRM) was then done to ascertain the quality of the interfaces and to check for interdiffusion between layers. MIM structures in the Coplanar Waveguide (CPW) configuration were fabricated using conventional lithography and etching techniques for high frequency measurements. The performance of the fabricated varactors was characterized from 100 MHz to 1 GHz. For the SAW application, structural characterization of Ba0.8Sr0.2TiO3 on Chemical Vapor Deposited (CVD) diamond was done and the deposition procedure was optimized to obtain thick BST films. SAW bandpass filters and resonators were designed wherein the device geometry was varied over a wide range in order to characterize the variation in device performance with geometry. Finally interdigital capacitor structures were fabricated and used for conducting Curie temperature measurements on the deposited BST films in order to determine the operation range of the deposited BST films.
Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
ABSTRACT: The composition-dependent Curie temperature and bias-dependant dielectric permittivity of Barium Strontium Titanate (BST) makes it very attractive for tunable application in the RF/Microwave regime. In this research work, the performance of BST varactors fabricated on the conventional Pt/Ti/SiO2/Si bottom electrode stack were compared with those fabricated using chemical vapor deposited Nanocrystalline Diamond (NCD) as the diffusion barrier layer instead of SiO2. The varactors fabricated on NCD films displayed much better symmetry in capacitance-voltage behavior and better overall quality factors than varactors fabricated on SiO2. The improvement in performance can be attributed to existence of stable interfaces in the devices fabricated on NCD which reduced the bottom electrode losses at high frequencies. The SiO2 based BST varactors on the other hand displayed better reliability and breakdown fields. The main purpose of this research work is to develop a robust Metal Insulator Metal (MIM) structure to achieve better all round performance of BST varactors. In the second part of this research work, the prospect of developing diamond based layered Surface Acoustic Wave (SAW) devices using Ba0.8Sr0.2TiO3 as the piezoelectric layer is investigated. Structural characterization of BST thin films deposited on Si/NCD/Pt and Si/SiO2/Ti/Pt stack were performed using X-Ray Diffraction (XRD) and Atomic Force Microscopy (AFM). Cross-sectional studies on the two stacks were performed using Scanning Electron Microscopy (SEM). X-Ray Mapping (XRM) was then done to ascertain the quality of the interfaces and to check for interdiffusion between layers. MIM structures in the Coplanar Waveguide (CPW) configuration were fabricated using conventional lithography and etching techniques for high frequency measurements. The performance of the fabricated varactors was characterized from 100 MHz to 1 GHz. For the SAW application, structural characterization of Ba0.8Sr0.2TiO3 on Chemical Vapor Deposited (CVD) diamond was done and the deposition procedure was optimized to obtain thick BST films. SAW bandpass filters and resonators were designed wherein the device geometry was varied over a wide range in order to characterize the variation in device performance with geometry. Finally interdigital capacitor structures were fabricated and used for conducting Curie temperature measurements on the deposited BST films in order to determine the operation range of the deposited BST films.
Microstructural and Electrical Characterization of Barium Strontium Titanate-Based Solid Solution Thin Films Deposited on Ceramic Substrates by Pulsed Laser Deposition
Author: Costas G. Fountzoulas
Publisher:
ISBN:
Category :
Languages : en
Pages : 6
Book Description
Ferroelectrics are multicomponent materials with a wealth of interesting and useful properties, such as piezoelectricity. The dielectric constant of the BSTO ferroelectrics can be changed by applying an electric field. Variable dielectric constant results in a change in phase velocity in the device allowing it to be tuned in real time for a particular application. The microstructure of the film influences the electronic properties which in turn influences the performance of the film. Ba(0.6)Sr(0.4)Ti(1-y)(A(3+), B(5+))(y)O3 thin films, of nominal thickness of 0.65 micrometer, were synthesized initially at substrate temperatures of 400 deg C, and subsequently annealed to 750 deg C, on LaAlO3 (100) substrates, previously coated with LaSrCoO conductive buffer layer, using the pulsed laser deposition technique. The microstructural and physical characteristics of the post-annealed thin films have been studied using x-ray diffraction, scanning electron microscopy, and nano indentation and are reported. Results of capacitance measurements are used to obtain dielectric constant and tunability in the paraelectric (T>Tc) regime.
Publisher:
ISBN:
Category :
Languages : en
Pages : 6
Book Description
Ferroelectrics are multicomponent materials with a wealth of interesting and useful properties, such as piezoelectricity. The dielectric constant of the BSTO ferroelectrics can be changed by applying an electric field. Variable dielectric constant results in a change in phase velocity in the device allowing it to be tuned in real time for a particular application. The microstructure of the film influences the electronic properties which in turn influences the performance of the film. Ba(0.6)Sr(0.4)Ti(1-y)(A(3+), B(5+))(y)O3 thin films, of nominal thickness of 0.65 micrometer, were synthesized initially at substrate temperatures of 400 deg C, and subsequently annealed to 750 deg C, on LaAlO3 (100) substrates, previously coated with LaSrCoO conductive buffer layer, using the pulsed laser deposition technique. The microstructural and physical characteristics of the post-annealed thin films have been studied using x-ray diffraction, scanning electron microscopy, and nano indentation and are reported. Results of capacitance measurements are used to obtain dielectric constant and tunability in the paraelectric (T>Tc) regime.
Intrinsic and Substrate Dependent Properties of Polycrystalline Barium Titanate Thin Films
Author: Kenneth Morian Ring
Publisher:
ISBN:
Category :
Languages : en
Pages : 456
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages : 456
Book Description
Ceramic Abstracts
Author:
Publisher:
ISBN:
Category : Ceramics
Languages : en
Pages : 500
Book Description
Publisher:
ISBN:
Category : Ceramics
Languages : en
Pages : 500
Book Description