A Novel Bidirectional AlGaN/GaN ESD Protection Diode

Area of Science:

• Materials Science
• Electrical Engineering
• Semiconductor Physics

Background:

• Gallium Nitride (GaN)-based High Electron Mobility Transistors (HEMTs) offer superior performance but are susceptible to electrostatic discharge (ESD) events.
• The gate structure in p-GaN or MOS HEMTs is particularly vulnerable, necessitating improved ESD protection.
• Existing solutions often lack bidirectional protection, creating a critical need for robust ESD diodes in GaN power systems.

Purpose of the Study:

• To propose and investigate a novel AlGaN/GaN ESD protection diode with bidirectional clamp capability.
• To enhance the ESD robustness of GaN power systems by addressing the vulnerability of gate structures.
• To explore the relationship between capacitor values and the triggering voltage and secondary breakdown current of the proposed diode.

Main Methods:

• Design and fabrication of an AlGaN/GaN ESD protection diode incorporating floating gate electrodes and parallel capacitors (CGA/CGC).
• Experimental investigation of the diode's triggering voltage (Vtrig) and secondary breakdown current (IS) under forward and reverse transient ESD events.
• Systematic variation of capacitor values (5 pF to 25 pF) to analyze their impact on ESD performance.

Main Results:

• The proposed diode demonstrated effective bidirectional clamping capability for transient ESD events.
• A clear correlation was observed between capacitor values (CGA/CGC) and the diode's ESD performance.
• Increasing CGA/CGC from 5 pF to 25 pF reduced Vtrig from ~18 V to ~7 V and IS from ~7 A to ~3 A.

Conclusions:

• The developed AlGaN/GaN ESD protection diode offers a viable solution for improving the ESD robustness of GaN power systems.
• The bidirectional clamping capability and tunable performance make it suitable for protecting vulnerable gate structures.
• The study provides valuable insights for the ESD design and optimization of GaN-based electronic systems.