Growth of High Permittivity Dielectrics by High Pressure Sputtering from Metallic Targets

Supervisor’s Foreword

Abstract

Acknowledgements

Contents

Abbreviations

Symbols

1 Introduction

1.1 Historical Evolution

1.2 CMOS Devices Scaling

1.3 High ? Dielectrics

1.3.1 Gadolinium Oxide

1.3.2 Scandium Oxide

1.3.3 Gadolinium Scandate

1.4 Metal Gate Electrodes

1.4.1 Scavenging Effect

1.5 Alternative Substrates

1.6 High Pressure Sputtering (HPS)

1.7 Alternatives Structures

1.8 Outline of the Thesis

References

2 Fabrication Techniques

2.1 High Pressure Sputtering (HPS)

2.2 Glow Discharge Optical Spectroscopy (GDOS)

2.2.1 System I (Monocromator)

2.2.2 System II (Spectrometer)

2.3 Electron Beam (e-beam) Evaporation

2.3.1 SiOx Acting as Field Oxide

2.3.2 Metallic Electrodes

2.4 Lithography Process

2.4.1 Positive Photoresist

2.4.2 Negative Photoresist

2.5 Rapid Thermal Annealing (RTA)

2.6 MIS Fabrication

2.6.1 Process Without Field Oxide (FOX)

2.6.2 Process with FOX

2.7 Substrates

2.7.1 Semiconductor Materials

2.7.1.1 Si Wafers

2.7.1.2 InP Substrates

2.7.2 Substrate Surface Cleaning

2.7.2.1 Si Wafers

2.7.2.2 InP Wafers

References

3 Characterization Techniques

3.1 Structural Characterization Techniques

3.1.1 Fourier Transform Infrared Spectroscopy (FTIR)

3.1.2 Grazing Incidence X Ray Diffraction (GIXRD)

3.1.3 X Ray Reflectometry (XRR)

3.1.4 X Ray Photoelectron Spectroscopy (XPS)

3.1.5 Transmission Electron Microscopy (TEM)

3.2 Electrical Characterization Techniques

3.2.1 MIS Capacitors

3.2.1.1 Ideal MIS Capacitor in Equilibrium

3.2.1.2 Ideal MIS Capacitor Under Bias

3.2.1.3 Real MIS Structure

3.2.2 Capacitive Behavior of MIS Devices: C–Vgate Characterization

3.2.2.1 Effects of QINS in the C–Vgate Characteristics

3.2.2.2 Effects of Dit in the C–Vgate Characteristics

3.2.2.3 Effects of the Oxide Trapped Charge in the C–Vgate Characteristics

3.2.3 Interfacial State Density (Dit) Determination

3.2.3.1 Conductance Method

3.2.3.2 Deep Level Transient Spectroscopy (DLTS)

3.2.4 Leakage Current Density Measurements

References

4 Thermal Oxidation of Gd2O3

4.1 Experimental Method

4.2 Results and Discussion

4.2.1 Plasma Characterization of Metallic Gd Sputtered in Ar

4.2.2 Physical Characterization of the Thermally Oxidized GdOx Films

4.2.3 Electrical Characterization of MIS Devices with Thermally Oxidized Gd2O3

4.2.4 TEM Analysis of MIS Devices

4.3 Summary and Conclusions

References

5 Plasma Oxidation of Gd2O3 and Sc2O3

5.1 Experimental Method

5.2 Results and Discussion

5.2.1 Feasibility of the Two-Step Deposition Process for Gd2O3 and Sc2O3

5.2.1.1 Plasma Characterization of Metallic Gd Sputtered in Ar/O2 Atmosphere

5.2.1.2 Plasma Characterization of Metallic Sc Sputtered in Pure Ar and Mixed Ar/O2 Atmospheres

5.2.1.3 Structural Characterization of the Plasma Oxidized Gd2O3 Films

5.2.1.4 Structural Characterization of the Plasma Oxidized Sc2O3 Films

5.2.1.5 Electrical Characterization of MIS Devices with Plasma Oxidized Gd2O3 and Sc2O3

5.2.2 Optimization of the Two-Step Deposition Process for Gd2O3

5.2.2.1 Oxidation Power Effect

5.2.2.2 Initial Metal Deposition Time Influence

5.2.2.3 Oxidation Time

5.2.3 Effect of FGA Temperature on Optimized MIS Devices with Plasma Oxidized Gd2O3

5.2.4 Electrical Characterization of Optimized MIS Devices with Plasma Oxidized Sc2O3

5.3 Summary and Conclusions

References

6 Gadolinium Scandate

6.1 Experimental Method

6.2 Results and Discussion

6.2.1 Plasma Characterization

6.2.2 Physical Characterization

6.2.3 Electrical Characterization

6.3 Summary and Conclusions

References

7 Interface Scavenging

7.1 Experimental Method

7.2 Results and Discussion

7.2.1 Thick Ti Layers as Top Electrode with Gd2O3

7.2.2 Optimization of the Scavenging Effect for Plasma Oxidized Gd2O3

7.2.3 Scavenging Effect for Plasma Oxidized Sc2O3

7.2.4 Scavenging Effect for Plasma Oxidized Gd0.9Sc1.1O3

7.3 Summary and Conclusions

References

8 Gd2O3 on InP Substrates

8.1 Experimental Method

8.2 Results and Discussion

8.2.1 Feasibility of Plasma Oxidized Gd2O3 Deposited on InP Substrates

8.2.2 Optimized Devices with Gd2O3 on InP

8.2.3 Interface Scavenging with InP

8.3 Summary and Conclusions

References

9 Conclusions and Future Work

9.1 Conclusions

9.2 Future Work

Curriculum Vitae

Education

Publication List

Conference Contributions

Patent

Research Experience

Teaching Experience