This paper reports on the isolation properties and failure mechanism of n-type vertical Pt / n-GaN Schottky barrier diodes and the dependence on the drift layer doping concentration. The results indicate that (i) independently on doping density, the Schottky barrier height is lower than the theoretical expectation, and this limits the blocking properties of the junction; (ii) barrier lowering was associated to an injection mechanism that involves deep levels in the semiconductor layer, near the junction, favouring injection and tunneling of carriers. By performing a detailed analysis of the breakdown mechanism, we also demonstrated that (iii) the failure of the devices in reverse bias condition is related to a power-related mechanism associated to current flowing along the mesa edges. We thus conclude that (iv) a good edge termination and passivation of the surfaces is fundamental to exploit the full blocking capability of the semiconductor.

本文报道了n型垂直Pt/ n的隔离特性和失效机理-GaN肖特基势垒二极管和漂移层掺杂浓度的依赖关系。结果表明：（i）与掺杂密度无关，肖特基势垒高度低于理论预期，这限制了结的阻挡特性；(ii) 势垒降低与一种注入机制有关，该注入机制涉及半导体层中的深能级，靠近结，有利于载流子的注入和隧穿。通过对击穿机制进行详细分析，我们还证明（iii）器件在反向偏置条件下的故障与与沿台面边缘流动的电流相关的功率相关机制有关。