Avalanche Ruggedness of GaN p-i-n Diodes Grown on Sapphire Substrate

Abstract

Avalanche capability plays critical roles in safe operation of GaN‐based high power devices and systems. In this study, GaN‐based quasi‐vertical p‐i‐n diodes on sapphire substrate with avalanche capability are fabricated, and for the first time, their avalanche ruggedness is investigated. Repeated avalanche breakdown tests suggest the representative features of avalanche‐capability degradation, reduction in breakdown voltage, and rise in reverse leakage current. Further numerical simulations reveal the localization of avalanche breakdown, while subsequent pulsed current–voltage measurements identify that the thermal heating effect generated during localized avalanche multiplication is responsible for the device degradation in avalanche ruggedness.

GaN Single Nanowire p–i–n Diode for High-Temperature Operations

“…The use of III-nitride (III-N) semiconductor materials for various energy-efficient optoelectronic and electronic devices has been extensively investigated due to III-N’s wide energy band gap, high critical electrical field, and good thermal stability. − GaN p–i–n diode is a fundamental and important device for a number of applications, such as rectifiers, photodetectors (PDs), microwave switches, solar cells, and so on. − There has been tremendous progress in recent years on thin film-based GaN p–i–n diodes on native GaN substrates and foreign substrates. − Despite outstanding device performance obtained for GaN p–i–n diodes grown on native GaN substrates, bulk GaN substrates with low-defect density are still expensive and only available in small sizes, limiting their use for volume productions. GaN p–i–n diodes grown on foreign substrates, such as Si and sapphire, show dislocation density in the range of 10 6 –10 9 /cm 2 , depending on the lattice constant mismatch level, thin film thickness, and growth methods. ,, Wide energy band gap III-N materials are also promising for monitoring and detecting signals in high-temperature environments, , such as furnaces, combustion chambers, and so on.…”

Device Design Assessment of GaN Merged P-i-N Schottky Diodes

“…GaN-based P-i-N diodes have been demonstrated for a number of substrates, including GaN [10][11][12][13][14], SiC [15], sapphire [16][17][18], and Si [19][20][21][22]. So far, GaN P-i-N diodes with breakdown voltages over 4 kV have been reported employing a drift layer thickness of over 30 µm grown on native GaN substrates [23].…”

Polarization Engineering to Manipulate the Breakdown Voltage for GaN‐Based PIN Diodes

“…One of the major missions is to increase the breakdown voltage for GaN‐based PIN diodes, and for that purpose, different design proposals have been suggested. First, the breakdown voltage can be increased if the electric field in the drift layer can be homogenized, e.g., by using field plates, field rings, and merged junctions that are also reversely biased when the device is in the blocking mode . Second, the enhanced breakdown voltage is possible by passivating the surface imperfections .…”