具有栅介质电场屏蔽作用的新型GaN纵向槽栅MOSFET器件设计  

Design of Novel Vertical GaN-Based Trench Gate MOSFET with Electric Field Shielding Function of Gate Dielectric

作　　者：黎城朗 吴千树 周毓昊 张津玮 刘振兴 张琦 刘扬 LI Chenglang;WU Qianshu;ZHOU Yuhao;ZHANG Jinwei;LIU Zhenxing;ZHANG Qi;LIU Yang(School of Electronics and Information Technology,Sun Yat-Sen University,Guangzhou 510006,CHN;Institute of Power Electronics and Control Technology,Sun Yat-Sen University,Guangzhou 510275,CHN;Guangdong Third Generation Semiconductor GaN Power Electronic Materials and Device Engineering Technology Research Center,Guangzhou 510275,CHN)

机构地区：[1]中山大学电子与信息工程学院,广州510006 [2]中山大学电力电子及控制技术研究所,广州510275 [3]广东省第三代半导体GaN电力电子材料与器件工程技术研究中心,广州510275

出　　处：《半导体光电》2022年第3期466-471,共6页Semiconductor Optoelectronics

基　　金：广东省重点领域研发计划资助项目(2020B010174003)。

摘　　要：基于氮化镓(GaN)等宽禁带(WBG)半导体的金氧半场效应晶体管(MOSFET)器件在关态耐压下,栅介质中存在与宽禁带半导体临界击穿电场相当的大电场,致使栅介质在长期可靠性方面受到挑战。为了避免在GaN器件中使用尚不成熟的p型离子注入技术,提出了一种基于选择区域外延技术制备的新型GaN纵向槽栅MOSFET,可通过降低关态栅介质电场来提高栅介质可靠性。提出了关态下的耗尽区结电容空间电荷竞争模型,定性解释了栅介质电场p型屏蔽结构的结构参数对栅介质电场的影响规律及机理,并通过权衡器件性能与可靠性的关系,得到击穿电压为1200 V、栅介质电场仅0.8 MV/cm的具有栅介质长期可靠性的新型GaN纵向槽栅MOSFET。Metal-oxide-semiconductor field effect transistor(MOSFET)devices based on wide bandgap(WBG)semiconductors such as gallium nitride(GaN)have a high electric field equivalent to the critical breakdown electric field of WBG semiconductor in the gate dielectric under the off-state voltage,which dampens the long-term reliability of the gate dielectric.In order to avoid using the immature p-type ion implantation technology in GaN devices,a new type of vertical GaN-based trench gate MOSFET based on selective area epitaxy is proposed,which can improve the gate dielectric reliability by reducing the off-state gate dielectric electric field.And a process preparation based on selective region epitaxy is designed to avoid the etching damage of MOS interface.The space charge competition model of the depletion region junction capacitance in the off-state is proposed,and the influence law and mechanism of the structural parameters of p-type shielding structure on the gate dielectric electric field are qualitatively explained.By trade off the relationship between device performance and reliability,a novel vertical GaN-based trench gate MOSFET with long-term reliability of gate dielectric is obtained with the breakdown voltage of 1200 V and gate dielectric electric field of 0.8 MV/cm.

关 键 词：氮化镓 栅介质可靠性 功率MOSFET 纵向槽栅结构 电场屏蔽 

分 类 号：TN386.2[电子电信—物理电子学]