The Influence of Recessed Floating Metal Rings Structure on Electrical Properties of AlGaN/GaN Schottky Barrier Diodes

Abstract

AlGaN/GaN lateral Schottky barrier diodes (SBDs) with the nonrecessed and recessed floating metal rings (FMR) structure are fabricated and electrically characterized to study the influence of recessed FMR structure. The recessed FMR SBDs (RFMR‐SBDs) exhibit the lower onset voltage (V ON) and higher forward current (I F) at the anode of 3 V than the nonrecessed FMR SBDs (FMR‐SBDs). More importantly, the breakdown voltage (V BR) of the RFMR‐SBDs is 1980 V, which has a significant improvement compared with the FMR‐SBDs of 1540 V. However, the specific on‐resistance of the RFMR‐SBDs is higher than FMR‐SBDs. Furthermore, the electric field distributions of different structures are simulated by Silvaco software to analyze the mechanism of improving breakdown voltage. The results show that the breakdown voltage improvement is due to the broader depletion region in the RFMR‐SBDs at the breakdown voltage. Moreover, the electric field distributions of the RFMR‐SBDs and FMR‐SBDs with three FMRs are discussed further.

On the super-junction formed by using field plate for lateral AlGaN/GaN-based Schottky barrier diodes

“…6,7) The breakdown voltage (BV) is directly influenced by the electric field distribution, such that the very strong local electric field at the Schottky contact region shall be avoided. 8) The electric field profile can be homogenized by using such as the gated-edge termination, [9][10][11] tri-anode configuration, 12) field plates (FPs), [13][14][15][16][17][18] floating metal rings, 19,20) p-GaN termination [21][22][23][24] and polarization-induced electric field effect. 25) Among these candidates, FP structures have been widely used because of the easier technical process and the effective charge-coupling effect.…”