Recent development of vertical GaN power devices

Abstract

Gallium nitride (GaN) is an attractive material for high-frequency and high-power devices. Due to the availability of relatively high-quality free-standing bulk GaN substrates, the research and development of vertical GaN devices on GaN substrates has made significant progress in recent years, and various transistors and diodes based on vertical GaN with excellent characteristics have been reported. This paper reviews the current status and recent progress of vertical GaN power device development reported from companies and research institutions, which includes the technological development of our recent research results of Schottky barrier diodes and trench MOSFETs. Key remaining issues for practical applications are also described.

Optimization of Mesa Etch for a Quasi-Vertical GaN Schottky Barrier Diode (SBD) by Inductively Coupled Plasma (ICP) and Device Characteristics

“…As a wide-bandgap semiconductor material, gallium nitride (GaN) has attracted increasing attention in recent years, attributed to its superior material properties such as wide bandgap, high electron saturation velocity, and high critical electric field [1]. The excellent performance of GaN-based vertical devices has revealed significant potential for high-power and high-frequency applications [2,3]. In addition to the conventional GaN self-standing substrate, epitaxial growth can be carried out on lower-cost and larger-scale foreign substrates (e.g., silicon, sapphire).…”

Analytical Models of Breakdown Voltage and Specific On-Resistance for Vertical GaN Unipolar Devices

“…Gallium nitride (GaN) power switching devices are promising as ideal candidates in the high power and high frequency applications, leveraging the well-recognized advantageous wide-band-gap material properties such as high breakdown field strength, high electron mobility, high electron saturation velocity and high working temperature [1], [2]. The high quality free-standing bulk GaN substrates with low dislocation density have facilitated the fabrication of the vertical GaN power devices including the p-n junction diodes [3]- [6], Schottky Barrier Diodes [7], [8] and transistors [9]- [12].…”

Challenges and Perspectives for Vertical GaN-on-Si Trench MOS Reliability: From Leakage Current Analysis to Gate Stack Optimization

“…Fully vertical GaN-on-GaN diode and transistor demonstrators have reported excellent performances (up to 3-4 kV capability [16][17][18][19][20][21][22][23][24]). However, GaN substrates are small and expensive, with wafer costs per unit area for GaN-on-GaN ranging up to $ 100/cm 2 for 2-inch wafers [25,26].…”