Multizone Gradient-Modulated Guard Ring Technique for Ultrahigh Voltage 4H-SiC Devices With Increased Tolerances to Implantation Dose and Surface Charges
Multizone Gradient-Modulated Guard Ring Technique for Ultrahigh Voltage 4H-SiC Devices With Increased Tolerances to Implantation Dose and Surface Charges
复制标题
用于超高压 4H-SiC 器件的多区梯度调制保护环技术，提高了对注入剂量和表面电荷的耐受性
DOI：
10.1109/jestpe.2019.2910610
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发表时间：
2019-09-01
影响因子：
5.5
通讯作者：
Zhang, Bo
中科院分区：
文献类型：
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作者：
Deng, Xiaochuan;Gao, Shufeng;Zhang, Bo
提出了一种面积有效的多区梯度调制保护环（MGM-GR）边缘终止技术，制造和分析10 kV级碳化硅器件，无需额外的工艺步骤或掩模，它提供了一个更好的折衷接近理想的阻断能力和工艺过程的复杂性。采用MGM-GR技术将边缘终止区划分为多个区域，形成类似线性渐变的掺杂分布，以减轻有源区外围的电场拥挤量，并实现对注入剂量具有宽容忍度的最大阻断电压。所提出的设备示出了不少于35%的减少边缘终端面积相比，在10千伏的击穿电压与传统的等距环。此外，MGM-GR表现出良好的耐受性，总注入剂量和界面电荷的击穿电压。将MGM-GR技术应用于厚度为100<inline-formula><tex-math notation="LaTeX">μ m</tex-math></inline-formula>的N<sup>-</sup>外延层掺杂为<inline-formula><tex-math notation="LaTeX">5 × 10^{14}$</tex-math></inline-formula>cm<inline-formula><tex-math notation="LaTeX">$^{-3}$的</tex-math></inline-formula>SiC MOSFET，测得击穿电压为13.6 kV（<inline-formula><tex-math notation="LaTeX">10 μ A）</tex-math></inline-formula>。这个电压是为1-D结构计算的理论值的近95%。模拟和实测特性表明，MGM-GR结构是一种可用于中压功率器件的候选结构，可以最大限度地提高功率密度，降低系统复杂度。
An area efficient multizone gradient-modulated guard ring (MGM-GR) edge termination technique is proposed, fabricated, and analyzed for 10-kV class silicon carbide devices without extra process steps or masks, which provides a better tradeoff between near ideal blocking capabilities and technological process complexity. The edge termination region is divided into multiple zones by employing MGM-GR technique, which forms a similar linearly graded doping profile to relieve the amount of electric field crowding at the periphery of the active area and achieve a maximum blocking voltage with wide tolerance to implantation dose. The proposed device shows not less than a 35% reduction in edge termination area in comparison with a conventional equally spaced ring at a breakdown voltage of 10 kV. Moreover, MGM-GR shows good tolerances to breakdown voltage for total implant dose and interface charges. With the application of MGM-GR technique to SiC MOSFET with a 100-<inline-formula> <tex-math notation="LaTeX">$\mu \text{m}$ </tex-math></inline-formula>-thick N<sup>−</sup> epilayer doped to <inline-formula> <tex-math notation="LaTeX">$5 \times 10^{14}$ </tex-math></inline-formula> cm<inline-formula> <tex-math notation="LaTeX">$^{-3}$ </tex-math></inline-formula>, the measured breakdown voltage is 13.6 kV at <inline-formula> <tex-math notation="LaTeX">$10~\mu \text{A}$ </tex-math></inline-formula>. This voltage is nearly 95% of the theoretical value calculated for a 1-D structure. Simulated and measured characteristics show that MGM-GR structure is a candidate for an ultrahigh voltage power device to maximize power density and driving down system complexity.