You are previewing Ferroelectric Dielectrics Integrated on Silicon.
O'Reilly logo
Ferroelectric Dielectrics Integrated on Silicon

Book Description

This book describes up-to-date technology applied to high-K materials for More Than Moore applications, i.e. microsystems applied to microelectronics core technologies.

After detailing the basic thermodynamic theory applied to high-K dielectrics thin films including extrinsic effects, this book emphasizes the specificity of thin films. Deposition and patterning technologies are then presented. A whole chapter is dedicated to the major role played in the field by X-Ray Diffraction characterization, and other characterization techniques are also described such as Radio frequency characterization. An in-depth study of the influence of leakage currents is performed together with reliability discussion. Three applicative chapters cover integrated capacitors, variables capacitors and ferroelectric memories. The final chapter deals with a reasonably new research field, multiferroic thin films.

Table of Contents

  1. Cover
  2. Title Page
  3. Copyright
  4. Preface
  5. Chapter 1: The Thermodynamic Approach
    1. 1.1. Background
    2. 1.2. The functions of state
    3. 1.3. Linear equations, piezoelectricity
    4. 1.4. Nonlinear equations, electrostriction
    5. 1.5. Thermodynamic modeling of the ferroelectric–paraelectric phase transition
      1. 1.5.1. Assumption on the elastic Gibbs energy
      2. 1.5.2. Second-order transition
      3. 1.5.3. Effect of stress
      4. 1.5.4. First-order transition
    6. 1.6. Conclusion
    7. 1.7. Bibliography
  6. Chapter 2: Stress Effect on Thin Films
    1. 2.1. Introduction
    2. 2.2. Modeling the system under consideration
    3. 2.3. Temperature–misfit strain phase diagrams for monodomain films
      1. 2.3.1. Phase diagram construction from the Landau–Ginzburg–Devonshire theory
      2. 2.3.2. Calculations limitations
    4. 2.4. Domain stability map
      1. 2.4.1. Presentation and description of the framework of study
      2. 2.4.2. Main contributions to the total energy of a film
      3. 2.4.3. Influence of thickness
      4. 2.4.4. Macroscopic elastic energy for each type of tetragonal domain
      5. 2.4.5. Indirect interaction energy
      6. 2.4.6. Domain structures at equilibrium
      7. 2.4.7. Domain stability map
        1. 2.4.7.1. Regions of existence
        2. 2.4.7.2. Regions of stability
        3. 2.4.7.3. Domain stability map
    5. 2.5. Temperature–misfit strain phase diagram for polydomain films
    6. 2.6. Discussion of the nature of the “misfit strain”
      1. 2.6.1. Mechanical misfit strain
      2. 2.6.2. Thermodynamic misfit strain
      3. 2.6.3. As an illustration
    7. 2.7. Conclusion
    8. 2.8. Experimental validation of phase diagrams: state of the art
    9. 2.9. Case study
    10. 2.10. Results
      1. 2.10.1. Evolution of the lattice parameters
      2. 2.10.2. Associated stresses and strains
        1. 2.10.2.1. Deposition stress
        2. 2.10.2.2. Inhomogeneous stresses
        3. 2.10.2.3. Differential thermal stress
        4. 2.10.2.4. Misfit strain
        5. 2.10.2.5. Mechanical strain
    11. 2.11. Comparison between the experimental data and the temperature–misfit strain phase diagrams
      1. 2.11.1. Thin film of PZT
      2. 2.11.2. Thin layer of PbTiO3
    12. 2.12. Conclusion
    13. 2.13. Bibliography
  7. Chapter 3: Deposition and Patterning Technologies
    1. 3.1. Deposition method
      1. 3.1.1. Cathodic sputtering
      2. 3.1.2. Ion beam sputtering
      3. 3.1.3. Pulsed laser deposition
      4. 3.1.4. The sol–gel process
      5. 3.1.5. The MOCVD
      6. 3.1.6. Molecular beam epitaxy
    2. 3.2. Etching
      1. 3.2.1. Wet etching
      2. 3.2.2. Dry etching
    3. 3.3. Contamination
    4. 3.4. Monocrystalline thin-film transfer
      1. 3.4.1. Smart Cut™ technology
      2. 3.4.2. Bonding/thinning
      3. 3.4.3. Interest in the material in a thin layer
      4. 3.4.4. State of the art of the domain/applications
        1. 3.4.4.1. Substrates obtained through transfer of monocrystalline layers
        2. 3.4.4.2. SAW filters
        3. 3.4.4.3. BAW filters
        4. 3.4.4.4. Optical applications
      5. 3.4.5. An exemplary implementation
        1. 3.4.5.1. Technology
        2. 3.4.5.2. Substrate characterization
    5. 3.5. Design of experiments
      1. 3.5.1. The assumptions
      2. 3.5.2. Reproducibility
      3. 3.5.3. How can we reduce the number of experiments?
      4. 3.5.4. A DOE example: PZT RF magnetron sputtering deposition
    6. 3.6. Conclusion
    7. 3.7. Bibliography
  8. Chapter 4: Analysis Through X-ray Diffraction of Polycrystalline Thin Films
    1. 4.1. Introduction
    2. 4.2. Some reminders of X-ray diffraction and crystallography
      1. 4.2.1. Nature of X-rays
      2. 4.2.2. X-ray scattering and diffraction
        1. 4.2.2.1. X-ray scatterings
          1. 4.2.2.1.1. X-ray scattering by an electron
          2. 4.2.2.1.2. X-ray scattering by an atom
          3. 4.2.2.1.3. X-ray scattering by a crystal
        2. 4.2.2.2. Principle of X-ray diffraction
          1. 4.2.2.2.1. Theory of the X-ray diffraction
          2. 4.2.2.2.2. Bragg’s equation
    3. 4.3. Application to powder or polycrystalline thin-films
    4. 4.4. Phase analysis by X-ray diffraction
      1. 4.4.1. Grazing incidence diffraction
      2. 4.4.2. De-texturing
      3. 4.4.3. Quantitative analysis
    5. 4.5. Identification of coherent domain sizes of diffraction and micro-strains
      1. 4.5.1. Analysis methodologies
        1. 4.5.1.1. Williamson-Hall method
    6. 4.6. Identification of crystallographic textures by X-ray diffraction
      1. 4.6.1. Texture analysis by a symmetric diffractogram
      2. 4.6.2. Pole figures and orientations distribution function
      3. 4.6.3. Measurement principle
      4. 4.6.4. Orientations distribution function
    7. 4.7. Determination of strains/stresses by X-ray diffraction
      1. 4.7.1. X-ray diffraction and strain
      2. 4.7.2. Determination of stresses from strains
      3. 4.7.3. Specificity of the X-ray diffraction in stress analysis
      4. 4.7.4. Equipment
      5. 4.7.5. Example of stress identification by the sin2ψ method
      6. 4.7.6. Precaution in the case of thin films
      7. 4.7.7. Application example for a BaxSr1−xTiO3 film
    8. 4.8. Bibliography
  9. Chapter 5: Physicochemical and Electrical Characterization
    1. 5.1. Introduction
    2. 5.2. Useful characterization techniques
      1. 5.2.1. Electron microscopy
        1. 5.2.1.1. Scanning electron microscopy
        2. 5.2.1.2. Transmission electron microscopy
      2. 5.2.2. Spectroscopy analysis
        1. 5.2.2.1. X-ray energy dispersive spectroscopy
        2. 5.2.2.2. Auger electron spectroscopy
        3. 5.2.2.3. Rutherford backscattering spectroscopy
        4. 5.2.2.4. Secondary ion mass spectrometry
        5. 5.2.2.5. Raman
    3. 5.3. Ferroelectric measurement
      1. 5.3.1. Sawyer–Tower assembly
      2. 5.3.2. “Virtual ground” assembly
    4. 5.4. Dielectric measurement
    5. 5.5. Bibliography
  10. Chapter 6: Radio-Frequency Characterization
    1. 6.1. Introduction
    2. 6.2. Notions and basic concepts associated with HF
      1. 6.2.1. Introduction to the phenomena associated with HF signals
      2. 6.2.2. Lumped or distributed behavior of an electric circuit
      3. 6.2.3. Notion of quadripoles: two-port circuits or four-terminal network [MÉS 85]
        1. 6.2.3.1. Definition
        2. 6.2.3.2. Y Z, and ABCD parameters associated with a quadripole
          1. 6.2.3.2.1. Z parameters
          2. 6.2.3.2.2. Y parameters
          3. 6.2.3.2.3. Chain parameters (ABCD parameters
        3. 6.2.3.3. Computing method of the Y Z, H, and ABCD parameters
        4. 6.2.3.4. Combination of quadripoles
          1. 6.2.3.4.1. Chain or cascade combination
          2. 6.2.3.4.2. Series combination
          3. 6.2.3.4.3. Parallel combination
      4. 6.2.4. Basic theoretical elements of transmission lines: HF electric model
      5. 6.2.5. HF electric model of a parallel MIM capacitor
      6. 6.2.6. Signal flow graph [BOR 93]
      7. 6.2.7. Scattering waves
      8. 6.2.8. Scattering parameters: S-parameters
      9. 6.2.9. Vector network analyzer (VNA)
    3. 6.3. Frequency analysis: HF characterization of materials
      1. 6.3.1. Objectives
      2. 6.3.2. Issues of HF measurements through a VNA
      3. 6.3.3. Calibration of the measuring system
      4. 6.3.4. Extraction of the propagation exponent of the transmission line: de-embedding associated with the TRL calibration
      5. 6.3.5. Extraction results of the complex permittivity of materials SrTiO3 and PbZrTiO3
    4. 6.4. Bibliography
  11. Chapter 7: Leakage Currents in PZT Capacitors
    1. 7.1. Introduction
    2. 7.2. Leakage current in metal/insulator/metal structures
      1. 7.2.1. Metal/insulator contact: definitions
        1. 7.2.1.1. Fermi level, work function, and electron affinity
        2. 7.2.1.2. Neutral contact
        3. 7.2.1.3. Blocking contact
        4. 7.2.1.4. Ohmic contact
        5. 7.2.1.5. Intrinsic and extrinsic carriers
      2. 7.2.2. Conduction mechanisms limited by the interfaces
        1. 7.2.2.1. Schottky emission
        2. 7.2.2.2. Tunneling conduction
      3. 7.2.3. Conduction mechanisms limited by the bulk of film
        1. 7.2.3.1. Poole-Frenkel emission
        2. 7.2.3.2. Hopping conduction
        3. 7.2.3.3. Conduction limited by the space charge
    3. 7.3. Problem of leakage current measurement
      1. 7.3.1. Relaxation current and true leakage current
        1. 7.3.1.1. Staircase procedure
        2. 7.3.1.2. Pulse procedure
      2. 7.3.2. Drift of true leakage current
      3. 7.3.3. Discussion
    4. 7.4. Characterization of the relaxation current
      1. 7.4.1. Origin of the relaxation current
      2. 7.4.2. Modeling of relaxation currents
        1. 7.4.2.1. Temperature evolution
        2. 7.4.2.2. Voltage evolution
      3. 7.4.3. Conclusion
    5. 7.5. Literature review of true leakage current in PZT
    6. 7.6. Dynamic characterization of true leakage current: I(t, T)
      1. 7.6.1. Study of the resistance degradation
        1. 7.6.1.1. State of the art
          1. 7.6.1.1.1. Role of oxygen vacancies
          2. 7.6.1.1.2. Role of the interfaces
        2. 7.6.1.2. Modeling of the resistance degradation
        3. 7.6.1.3. Temperature activation of the resistance degradation
        4. 7.6.1.4. Influence of voltage on resistance degradation
        5. 7.6.1.5. Discussion – interpretation of results
          1. 7.6.1.5.1. Influence of polarity: roles of bulk and interfaces
          2. 7.6.1.5.2. Capacitive measurements before and after degradation
          3. 7.6.1.5.3. Reversibility of the resistance degradation mechanism
        6. 7.6.1.6. Conclusion
      2. 7.6.2. Study of the resistance restoration phenomenon
        1. 7.6.2.1. Modeling the resistance restoration
        2. 7.6.2.2. Temperature activation of resistance restoration
        3. 7.6.2.3. Influence of voltage on the resistance restoration
      3. 7.6.3. Conclusion
    7. 7.7. Static characterization of the true leakage current: I(V,T)
      1. 7.7.1. Space-charge influenced-injection model
      2. 7.7.2. Quantitative description of the model
        1. 7.7.2.1. Ohmic regime
        2. 7.7.2.2. Static Schottky regime
        3. 7.7.2.3. Dynamic Schottky regime
      3. 7.7.3. Static modeling Jmin(V) and Jmax(V)
        1. 7.7.3.1. Experimental procedure
        2. 7.7.3.2. Modeling results
        3. 7.7.3.3. Discussion: consistency of the model
        4. 7.7.3.4. Temperature modeling of Jmax(V)
    8. 7.8. Conclusion
    9. 7.9. Bibliography
  12. Chapter 8: Integrated Capacitors
    1. 8.1. Introduction
    2. 8.2. Potentiality of perovskites for RF devices: permittivity and losses
      1. 8.2.1. RF MIM capacitors of STO and PZT
        1. 8.2.1.1. Used technology
        2. 8.2.1.2. Model and RF/LF tests
        3. 8.2.1.3. Results and discussions
          1. 8.2.1.3.1. Extraction of the model parameters from the RF measurements
          2. 8.2.1.3.2. Dielectric constants as a function of frequency
        4. 8.2.1.4. Conclusion
      2. 8.2.2. Coplanar line waveguides on PZT
        1. 8.2.2.1. Technology and model
        2. 8.2.2.2. Experimental results and discussion
      3. 8.2.3. How to perform a good integrated capacitor at RF frequencies?
        1. 8.2.3.1. Right impedance and quality factor
        2. 8.2.3.2. Dielectric losses
        3. 8.2.3.3. Electrodes
        4. 8.2.3.4. Area
        5. 8.2.3.5. Variation with polarization and temperature
    3. 8.3. Bi-dielectric capacitors with high linearity
      1. 8.3.1. Introduction
      2. 8.3.2. Design
      3. 8.3.3. Technology
      4. 8.3.4. Results
    4. 8.4. STO capacitors integrated on CMOS substrate by AIC technology
      1. 8.4.1. Introduction
      2. 8.4.2. Technology
      3. 8.4.3. Electrical tests
      4. 8.4.4. Conclusion
    5. 8.5. Bibliography
  13. Chapter 9: Reliability of PZT Capacitors
    1. 9.1. Introduction
    2. 9.2. Accelerated aging of metal/insulator/metal structures
      1. 9.2.1. The electrical stresses
        1. 9.2.1.1. Constant stress tests (CVS and CCS)
        2. 9.2.1.2. Ramp stress tests (LRVS and ERCS)
      2. 9.2.2. The breakdown
        1. 9.2.2.1. The percolation model
      3. 9.2.3. Statistical treatment of breakdown
        1. 9.2.3.1. Definitions: statistics reminders
          1. 9.2.3.1.1. Probability density f and cumulative distribution F functions
          2. 9.2.3.1.2. Reliability function R
          3. 9.2.3.1.3. Failure ratio function λ
          4. 9.2.3.1.4. Weibull statistical distribution
          5. 9.2.3.1.5. Estimation of adjustment parameters
            1. 9.2.3.1.5.1. Maximum likelihood method
            2. 9.2.3.1.5.2. Determination of confidence intervals
    3. 9.3. Accelerated aging of PZT capacitors through CVS tests
      1. 9.3.1. Literature review
      2. 9.3.2. Statistical study of time-to-breakdown data
        1. 9.3.2.1. Traditional voltage acceleration
        2. 9.3.2.2. Temperature acceleration at low voltage
      3. 9.3.3. Discussion: characterization strategy
        1. 9.3.3.1. Summary of reliability results obtained at wafer level
        2. 9.3.3.2. Implementation of package level reliability results
        3. 9.3.3.3. Conclusion
    4. 9.4. Lifetime extrapolation of PZT capacitors
      1. 9.4.1. Determination of the temperature acceleration factor
      2. 9.4.2. Determination of voltage acceleration
        1. 9.4.2.1. Classical lifetime extrapolation models for voltage or electric field acceleration
          1. 9.4.2.1.1. E model
          2. 9.4.2.1.2. 1/E model
          3. 9.4.2.1.3. Power law model
          4. 9.4.2.1.4. E1/2 model
          5. 9.4.2.1.5. Discussion
        2. 9.4.2.2. Additional data of reliability in packages: toward an E model
        3. 9.4.2.3. Conclusion
    5. 9.5. Conclusion
    6. 9.6. Bibliography
  14. Chapter 10: Ferroelectric Tunable Capacitors
    1. 10.1. Introduction
    2. 10.2. Overview of the tunable capacitors
      1. 10.2.1. Applications requiring a tunable element
      2. 10.2.2. The tunable capacitors
        1. 10.2.2.1. MOS varactor
        2. 10.2.2.2. MEMS
        3. 10.2.2.3. Ferroelectric capacitor
        4. 10.2.2.4. Conclusion
      3. 10.2.3. Which material to choose?
        1. 10.2.3.1. Note on the dielectric losses
    3. 10.3. Types of actual tunable capacitors
      1. 10.3.1. MIM capacitor
        1. 10.3.1.1. Origin of size effects
        2. 10.3.1.2. Crystalline strains
          1. 10.3.1.2.1. Dead layer phenomenon
      2. 10.3.2. Planar capacity
        1. 10.3.2.1. Conformal mapping
        2. 10.3.2.2. Comparison of the measure and the simulation
      3. 10.3.3. Anisotropy effects
    4. 10.4. Toward new tunable capacitors
      1. 10.4.1. Composite ferroelectric materials
        1. 10.4.1.1. State of the art
        2. 10.4.1.2. Modeling of a “spherical inclusions” composite
        3. 10.4.1.3. BST amorphous/crystalline composite
      2. 10.4.2. Hybrid tunable capacitor
        1. 10.4.2.1. The hybrid structure
        2. 10.4.2.2. Measurements on hybrid capacitors
    5. 10.5. Bibliography
  15. Chapter 11: FRAM Ferroelectric Memories: Basic Operations, Limitations, Innovations and Applications
    1. 11.1. Taxonomy of non-volatile memories
      1. 11.1.1. Present and future solutions
      2. 11.1.2. Difficult penetration of a highly competitive market
    2. 11.2. FRAM memories: basic operations and limitations
      1. 11.2.1. Charge storage in a ferroelectric capacitor
      2. 11.2.2. Ferroelectric materials
    3. 11.3. Technologies available in 2011
    4. 11.4. Technological innovations
      1. 11.4.1. 3D ferroelectric capacitors
      2. 11.4.2. Ferroelectric field effect transistors
      3. 11.4.3. What about ferroelectric polymers?
    5. 11.5. Some application areas of FRAM technology
      1. 11.5.1. An alternative to EEPROM memories
      2. 11.5.2. Ferroelectric devices for RFID systems
    6. 11.6. Conclusion
    7. 11.7. Bibliography
  16. Chapter 12: Integration of Multiferroic BiFeO3 Thin Films into Modern Microelectronics
    1. 12.1. Introduction
    2. 12.2. Preparation methods
      1. 12.2.1. Pulsed laser deposition
      2. 12.2.2. Chemical solution deposition
      3. 12.2.3. RF magnetron sputtering
    3. 12.3. Ferroelectricity and magnetism
      1. 12.3.1. Ferroelectricity
      2. 12.3.2. Magnetism
      3. 12.3.3. Magnetoelectric coupling
    4. 12.4. Device applications
      1. 12.4.1. Non-volatile ferroelectric memories
      2. 12.4.2. Spintronics
      3. 12.4.3. Terahertz radiation
      4. 12.4.4. Switchable ferroelectric diodes and photovoltaic devices
    5. 12.5. Bibliography
  17. List of Authors
  18. Index