Devices with adjustable dual-polarity trigger- and holding-voltage/current for high level of electrostatic discharge protection in sub-micron mixed signal cmos/bicmos integrated circuits

Abstract

Symmetrical/asymmetrical bidirectional S-shaped I-V characteristics with trigger voltages ranging from 10 V to over 40 V and relatively high holding current are obtained for advanced sub-micron silicided CMOS (Complementary Metal Oxide Semiconductor)/BiCMOS (Bipolar CMOS) technologies by custom implementation of P-N-P-N//N-P-N-Plateral structures with embedded ballast resistanceA,A and periphery guard-ring isolation-. The bidirectional protection devices render a high level of electrostatic discharge (ESD) immunity for advanced CMOS/BiCMOS processes with no latchup problems. Novel design-adapted multifinger/interdigitatedlayout schemes of the ESD protection cells allow for scaling-up the ESD performance of the protection structure and custom integration, while the I-V characteristicsare adjustable to the operating conditions of the integrated circuit (IC). The ESD protection cells are tested using the TLP (Transmission Line Pulse) technique, and ESD standards including HBM (Human Body Model), MM (Machine Model), and IEC (International Electrotechnical Commission) IEC 1000-4-2 standard for ESD immunity. ESD protection performance is demonstrated also at high temperature (140° C.). The unique high ratio of dual-polarity ESD protection level per unit area, allows for integration of fast-response and compact protection cells optimized for the current tendency of the semiconductor industry toward low cost and high density-oriented IC design. Symmetric/asymmetric dual polarity ESD protection performance is demonstrated for over 15 kV HBM, 2 kV MM, and 16.5 kV IEC for sub-micron technology.