Study of High-Performance GaN-Based Trench CAVET with Stepped Doping Microstructure

Area of Science:

• Materials Science
• Electrical Engineering
• Semiconductor Physics

Background:

• Gallium Nitride (GaN) based devices are crucial for high-power electronics.
• Current-aperture vertical electron transistors (CAVETs) offer potential for high performance.
• Optimizing breakdown voltage (BV) and specific on-resistance (R_on,sp) is critical for GaN CAVETs.

Purpose of the Study:

• To propose and investigate an innovative GaN-based trench CAVET featuring a stepped doping microstructure.
• To analyze the impact of the stepped doping microstructure on device performance metrics.
• To compare the performance of the proposed structure with conventional GaN-based trench CAVETs.

Main Methods:

• Device simulation using Silvaco-ATLAS software.
• Analysis of electric-field distribution modulation.
• Optimization of stepped doping microstructure dimensions and doping concentrations.

Main Results:

• Achieved a Baliga's figure of merit (FOM) of 4.767 GW·cm².
• Optimized device demonstrated a breakdown voltage (BV) of 2523 V with a specific on-resistance (R_on,sp) of 1.34 mΩ·cm².
• Further optimization yielded a BV of 3024 V with an R_on,sp of 2.08 mΩ·cm².
• The proposed structure showed a 43% reduction in R_on,sp and a 20% increase in BV compared to conventional designs.

Conclusions:

• The stepped doping microstructure in GaN-based trench CAVETs is superior for enhancing BV and reducing R_on,sp.
• The proposed device design offers significant improvements over conventional structures.
• This work provides valuable insights for the future development of advanced GaN-based power devices.