Designing ESD Protection Devices for Ultrafast Overvoltage Events
Designing ESD Protection Devices for Ultrafast Overvoltage Events
复制标题
设计针对超快过压事件的 ESD 保护器件
DOI：
10.1109/ted.2019.2941721
复制
发表时间：
2019
影响因子：
3.1
通讯作者：
Brian Moane
中科院分区：
文献类型：
--
作者：
E. Coyne;D. Clarke;Stephen Heffernan;Brian Moane
This article provides an understanding of the transient voltage overshoot physics observed with electro-static discharge (ESD) n-type, p-type, and n-type diffusions (NPN) bipolar devices through the use of calibrated technical computer-aided design (TCAD) with measured silicon results. This analysis graphically steps through each stage of the measured transient electrical response, to explain the inertia that limits the speed of the NPN ESD cell, and then uses this knowledge to provide a fully characterized silicon solution for ultrafast ESD events to achieve an 8-kV IEC61000-4-4 rating. This solution is developed by exploring five different integrated designs that are constructed on an 80-V bipolar and complimentary double-diffused metal-oxide semiconductor (BiCDMOS) process platform to protect against a product level 125-V voltage overshoot gate oxide ruptures as measured with a 0.6-ns rise time transmission line pulse (TLP). The fully characterized electrical results for each test overshoot structure with a fixed layout area of <inline-formula> <tex-math notation="LaTeX">$200\,\,\mu \text{m}\,\,\times200\,\,\mu \text{m}$ </tex-math></inline-formula>, are in parallel to NPN ESD cells arranged with two in series and two in parallel (<inline-formula> <tex-math notation="LaTeX">$200\,\,\mu \text{m}\,\,\times 80\,\,\mu \text{m}$ </tex-math></inline-formula>) and compared in terms of the current-carrying capability before the gate oxide rupture voltage of 125 V is reached. The results show that a diode engineered with a vertical breakdown achieves an ESD strength of 9.7 A before the overshoot voltage reaches the target of 125-V, resulting in a net 0.17 mA<inline-formula> <tex-math notation="LaTeX">$\mu \text{m}^{-{2}}$ </tex-math></inline-formula>. The combined use of this vertical diode structure in parallel to the NPN ESD cell translates into a 7-A improvement in the strength of a conventional NPN for ultrafast timescales, which achieves the 8-kV International Electrotechnical Commission (IEC) ESD performance for this case study.
