Ultra-low turn-on voltage and on-resistance vertical GaN-on-GaN Schottky power diodes with high mobility double drift layers
Abstract
This letter reports the implementation of double-drift-layer (DDL) design into GaN vertical Schottky barrier diodes (SBDs) grown on free-standing GaN substrates. This design balances the trade-off between desirable forward turn-on characteristics and high reverse breakdown capability, providing optimal overall device performances for power switching applications. With a well-controlled metalorganic chemical vapor deposition process, the doping concentration of the top drift layer was reduced, which served to suppress the peak electric field at the metal/GaN interface and increase the breakdown voltages of the SBDs. The bottom drift layer was moderately doped to achieve low on-resistance to reduce power losses. At forward bias, the devices exhibited a record low turn-on voltage of 0.59 V, an ultra-low on-resistance of 1.65 mΩ cm2, a near unity ideality factor of 1.04, a high on/off ratio of ∼1010, and a high electron mobility of 1045.2 cm2/(V s). Detailed comparisons with conventional single-drift-layer (SDL) GaN vertical SBDs indicated that DDL design did not degrade the forward characteristics of the SBDs. At reverse bias, breakdown voltages of the DDL GaN SBDs were considerably enhanced compared to those of the conventional SDL devices. These results showed that GaN vertical SBDs with DDL designs are promising candidates for high efficiency, high voltage, high frequency power switching applications.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Oct 09, 2017
- Source ID
- 10.1063/1.4993201
Entities
People
- Hong Chen
- Houqiang Fu
- Izak Baranowski
- Xuanqi Huang
- Yuji Zhao
- Zhijian Lu
Organizations
- Arizona State University
- Defense Threat Reduction Agency