关键词: 异质结势垒肖特基二极管(HJBS), 氮化镓, 硅, 陷阱辅助的多隧穿捕获与发射

Abstract: This paper presents the first study on the transport mechanism of a novel heterojunction barrier Schottky diode (HJBS) based on a GaN (p-PolySi) structure. The research results indicate that the operating mechanisms under both forward and reverse bias are associated with defects formed at the GaN/polySi heterojunction. Within the bias temperature range of -80~+80℃, the device exhibits different current transport mechanisms depending on the bias and temperature conditions. 1) Under forward bias, when the device is in the Region I (V_f < 0.5 V) and the temperature is above -20℃, the main conduction mechanism is the multi-tunnel capture-emission (MTCE) mode; 2) when the device is in Region I (V_f < 0.5 V) and the temperature is below -20℃, thermionic emission becomes the primary conduction mechanism, which is related to the uneven barrier height at the interface; 3) when the device is in Region Ⅱ (0.5 V < V_f < 0.9 V), Fowler-Nordheim (F-N) tunneling serves as the main conduction mechanism. All the transport mechanisms of the device's forward characteristics are associated with donor-like defects formed by carbon atoms in gallium nitride. On the other hand, under reverse bias, the leakage current mechanism of the degenerate device can be summarized as follows: at lower reverse voltages (V_r < 50 V), the barrier reduction effect dominates; at higher reverse voltages (V_r > 50 V), the space charge limited current (SCLC) mechanism prevails.

Key words: GaN, heterojunction barrier schottky diodes (HJBS), trap-assisted multi tunneling capture-emission