4H-SiC JBS沟槽结构的仿真研究
发布时间：2019-06-26 20:18
【摘要】：SiC作为第三代半导体中的佼佼者,具有优越的电学性能,能够工作在高温,大功率,高频等特殊环境下。而JBS作为高耐压,高速,大电流的功率二极管,被认为是发展最快,前景最好的一类二极管。本文针对平面JBS的不足,提出了一种改进结构-沟槽结构的JBS(TJBS),并用Sentaurus-TCAD软件进行了仿真优化,普通JBS由于受离子注入深度的限制,相邻的pn结势垒对中间的肖特基结的保护作用有限。引入沟槽后,pn结深度变得可以调整,TJBS可以获得更大的pn结结深,在相同间距下,电场屏蔽效应得以增强从而使器件的反向漏电流显著降低。首先研究了TJBS单胞结构,使用1200V的器件参数:外延层厚度10μm,掺杂浓度5×15/cm3,针对两种单胞结构-先注入后刻槽结构(TJBS_A)和先刻槽后注入结构(TJBS_B),通过对比发现:由于后者能够在相同注入能量条件下实现更大的注入深度,且工艺更简单,故其性能优于前者;随后针对TJBS_B,研究了槽深与注入深度相对性,槽宽与注入宽度相对性以及套刻偏差对其正反向特性的影响。只有在注入宽度大于槽宽的情况下才能发挥该结构降低反向漏电流的优势。在此条件情况下,注入深度越大反向漏电流越低。在允许的套刻偏差内(1μm以下),套刻偏差的存在对器件性能的影响较小。在相同注入深度和相同注入比的情况下沟槽JBS相比对平面JBS对肖特基区的保护作用更强,能够在相同击穿电压条件下获得更好的正向性能。然后研究了带有场限环终端的TJBS完整结构,加入了对终端刻槽的讨论,发现主结和场限环同时刻槽时器件的性能最优。
[Abstract]:As a leader in the third generation semiconductors, SiC has superior electrical properties and can work in high temperature, high power, high frequency and other special environments. As a high voltage, high speed and high current power diode, JBS is considered to be the fastest developing and the most promising diode. In order to overcome the shortcomings of plane JBS, an improved structure-groove structure JBS (TJBS), is proposed and optimized by Sentaurus-TCAD software. Due to the limitation of ion implantation depth, the potential barrier of adjacent pn junction has limited protective effect on the middle Schottky junction. With the introduction of grooves, the depth of pn junction can be adjusted, and the depth of pn junction can be obtained by TJBS. At the same spacing, the shielding effect of electric field can be enhanced, so that the reverse leakage current of the device can be significantly reduced. Firstly, the TJBS unit cell structure is studied. The device parameters of 1200 V are as follows: the thickness of epitaxial layer is 10 渭 m, the doping concentration is 5 脳 15 鈮，
本文编号：2506460
[Abstract]:As a leader in the third generation semiconductors, SiC has superior electrical properties and can work in high temperature, high power, high frequency and other special environments. As a high voltage, high speed and high current power diode, JBS is considered to be the fastest developing and the most promising diode. In order to overcome the shortcomings of plane JBS, an improved structure-groove structure JBS (TJBS), is proposed and optimized by Sentaurus-TCAD software. Due to the limitation of ion implantation depth, the potential barrier of adjacent pn junction has limited protective effect on the middle Schottky junction. With the introduction of grooves, the depth of pn junction can be adjusted, and the depth of pn junction can be obtained by TJBS. At the same spacing, the shielding effect of electric field can be enhanced, so that the reverse leakage current of the device can be significantly reduced. Firstly, the TJBS unit cell structure is studied. The device parameters of 1200 V are as follows: the thickness of epitaxial layer is 10 渭 m, the doping concentration is 5 脳 15 鈮，
本文编号：2506460
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