New Approaches For Designing
High Voltage, High Current
Silicon Step Recovery Diodes
for Pulse Sharpening Applications

by

Michael John Chudobiak, B.Sc. (Hons.)

© Copyright 1996, Michael J. Chudobiak

Title Page

Abstract

Acknowledgments

Table Of Contents

List of Tables

List of Figures

List of Symbols

Chapter 1 - Introduction

• 1.1 - Motivation
• 1.2 - New Approaches for Step Recovery Diodes
• 1.3 - Remarks on the Philosophy Adopted in This Study
• 1.4 - Main Contributions
• 1.5 - Organization

Chapter 2 - Review of Diode Reverse Transient Physics

• 2.1 - Introduction
• 2.2 - Review of Power Diode Switching Principles
  • 2.2.1 - Principles of Power Rectifier Operation - pin Diodes
  • 2.2.2 - Principles of Power Rectifier Operation - psn Diodes
  • 2.2.3 - Principles of Power Rectifier Operation - Diffused Diodes
• 2.3 - Review of Conventional Step Recovery Diode Switching Principles
• 2.4 - Difficulties with High Voltage Step Recovery Operation

Chapter 3 - Experimental Evidence from Commercial Devices

• 3.1 - Introduction
• 3.2 - Experimental Observations With Commercial Diodes
• 3.3 - Usefulness of Commercial Diodes as High-Voltage SRDs

Chapter 4 - Calculation of VBR for Diffused Diodes

• 4.1 - Introduction
• 4.2 - Basic Method
• 4.3 - Calculating EC
• 4.4 - Conclusions Regarding the Method of Calculating VBR
• 4.5 - Qualitative Observations on the Nature of VBR(λ,L)

• Chapter 5 - The Theory of Wide-Field Step Recovery Diodes (WFSRD)
• 5.1 - Remarks on the Philosophy Adopted in This Study
• 5.2 - Introductory Reference Structures
  • 5.2.1 - Abrupt Structures versus Diffused Structures
  • 5.2.2 - The Influence of Background Doping
• 5.3 - General Description of the New SRD Mechanism
• 5.4 - Parameter Determination
  • 5.4.1 - NB
  • 5.4.2 - VRAMP
  • 5.4.3 - The Transition Time tR
  • 5.4.4 - RC Time Constant
  • 5.4.5 - Storage Time ts
• 5.5 - Design Methodology
  • 5.5.1 - Optimization
• 5.6 - The Chosen Device
• 5.7 - Operating Range Limitations

Chapter 6 - Fabrication Method for WFSRD Devices

• 6.1 - Introduction
• 6.2 - General Approach
• 6.3 - Substrate Preparation and Dopant Implantation
• 6.4 - Dopant Drive-In Diffusion
• 6.5 - Lifetime Killers
• 6.6 - Metallization

Chapter 7 - Experimental Results for WFSRD Devices

• 7.1 - Introduction
• 7.2 - DC Measurements
• 7.3 - Series-Connected Pulse-Sharpening Operation
• 7.4 - Shunt-Connected Pulse-Sharpening Operation
• 7.5 - Discussion

Chapter 8 - The Theory of Drift Step Recovery Diodes (DSRD)

• 8.1 - Introduction
• 8.2 - The Forward Transient In pin Structures
• 8.3 - The Forward Transient In psn Structures
• 8.4 - Implications For Pulse Sharpening Diodes Design Theory
• 8.5 - DSRD Ramp Voltage
• 8.6 - DSRD Transition Times
• 8.7 - Other DSRD Issues
• 8.8 - Conclusion

Chapter 9 - Concluding Remarks

• 9.1 - Summation and Conclusions
• 9.2 - Alternative Approaches to High Speed Semiconductor Switching
• 9.3 - Future Work Beyond This Thesis

Appendix A - The High-Voltage CV Measurement Instrument

• A.1 - Introduction
• A.2 - Theory
• A.3 - Circuit Implementation
• A.4 - Discussion

Appendix B - A High Speed, Medium Voltage Pulse Amplifier For Diode Reverse Transient Measurements

• B.1 - Introduction
• B.2 - Amplifier Circuit
• B.3 - Application to Reverse Transient Measurements

Appendix C - The Relationship Between VBR and EC

• C.1 - Introduction
• C.2 - Theory

Appendix D - The Relationship Between tR and τ

• D.1 - Introduction
• D.2 - Computer Simulations

Appendix E - Thermal Considerations

• E.1 - Introduction
• E.2 - Theory

Appendix F - Sample Medici File

References