A Novel Dual-Direction SCR Embedded With Segmental and Cross-Bridge Topology for High-Voltage ESD Protection

Abstract

A novel dual-direction silicon-controlled rectifier (DDSCR) embedded with segmental and cross-bridge topology, which is named DDSCRESCT, is proposed and optimized for electrostatic discharge (ESD) protection. By segmenting N <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$^{+}$</tex-math> </inline-formula> bridges and inserting a P <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$^{+}$</tex-math> </inline-formula> bridge in DDSCR, the trigger voltage of the DDSCRESCT decreases to 10.3 V, which is attributed to the multiple avalanche breakdown effects. By embedding a floating N-type well in DDSCR, the holding voltage of the DDSCRESCT increases to 7.8 V, due to the low current gain of the parasitic bipolar junction transistors. Compared to DDSCR, the leakage current of the DDSCRESCT decreases about one order of magnitude and achieves a large failure current ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\textit{I}_{\textit{t}\text{2}}$</tex-math> </inline-formula> ) of 3.6 A, resulting from the segmental and cross-bridge topology design. By optimizing the length of the N <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$^{+}$</tex-math> </inline-formula> segmental topology and the width of the P <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$^{+}$</tex-math> </inline-formula> implanted bridge across the P-type well, the DDSCRESCT exhibits a good clamping ability and a decreased turn-on resistance of 2.1 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\Omega $</tex-math> </inline-formula> , resulting in a further <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\sim$</tex-math> </inline-formula> 16.2% increase of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\textit{I}_{\textit{t}\text{2}}$</tex-math> </inline-formula> . The human body model (HBM) test of the DDSCRESCT with a finger width of 100 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu $</tex-math> </inline-formula> m can reach 4 kV due to the optimized segmental and cross-bridge topology design, which also offers great potential in providing high-voltage ESD protection.