Building-in ESD/EOS reliability for sub-halfmicron CMOS processes

MOSFET design in high performance CMOS technologies is driven primarily by performance requirements and reliability issues such as hot carrier degradation. These requirements generally lead to processes that are inherently weak in terms of ESD and EOS. This paper presents a case of building-in ESD/EOS reliability through nMOSFET drain design for a 0.35 /spl mu/m CMOS process that compromises neither the performance nor the hot carrier reliability. Three process options were considered: nLDD or nDDD ESD implants, and a silicide-block option. The nDDD option for the I/O transistors was chosen as it complied with the performance and reliability (ESD and HCI) specifications and its implementation cost was lower than a silicide-block option. The paper presents data demonstrating the advantages of the nDDD solution over the other alternatives. Particularly, pulsed-EOS and HBM-ESD data, the impact of layout parameters on ESD performance, and hot-carrier data are reviewed.

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