High-voltage ESD structures and ESD protection concepts in smart power technologies
Creators: name: Cao, Yiqun
Publisher: name: Technische Universität Dortmund
Year: 2019
Subjects: subject: ESD
subject: Smart power technologies
subject: High-voltage
subject: ESD protection
subject: ESD modeling
subject: 620
subject: Smart Grid
subject: Elektrischer Überschlag
subject: Hochspannung

description: Electro-static discharge (ESD) event can cause upset or permanent damage of integrated circuits (IC) and electrical systems. The risk of ESD fails needs to be mitigated or prevented. ESD robustness of IC products and electrical systems is specified, verified and qualified according to respective ESD standards. For high-voltage IC products based on smart power semiconductor technologies for industrial, power and automotive applications, design of effective and cost-efficient ESD protection is a big challenge, demanding wide and deep technical knowledge throughout high-frequency and high-power characterization techniques, semiconductor device physic, circuit design as well as modeling and simulation. The required measurement setups and tester components are developed and introduced. The characterization of ESD protection devices, IC and off-chip circuit elements is enabled and improved. The rise-time filters are important for the study of rise-time dependent ESD robustness. The human metal model (HMM) tester as an alternative to IEC ESD generators provides voltage waveform measurement with good quality in addition to current waveform measurement. It can be used for wafer-level or package-level device characterization. The measurement results of HMM tester and IEC ESD generator are compared. The on-chip ESD protection design relies on proper choice of different types of ESD protection devices and structures, depending on ESD specifications and IC applications. Typical on-chip ESD protection, whether snapback or non-snapback, single device or ESD circuit is introduced. The failure levels studies give a systematic benchmark of the ESD protection devices and structures, concerning device area, clamping voltage and other relevant parameters. The trade-off between those parameters and limitation of different ESD protection is discussed. Moreover, understanding of ESD failure modes is the key to implement effective ESD design. A unique ESD failure mode of smart power semiconductor device is discovered and investigated in detail. In the scope of finding ESD solutions, new active ESD clamps have been further developed in this work. The study of ESD protection is extended to the system-level involving on- and off-chip ESD protection elements. The characteristics of typical off-chip elements as well as the interaction between IC and off-chip protection elements plays essential role on the system robustness. A system-level ESD simulation incorporating IC and off-chip protection elements is desired for system efficient ESD design (SEED). A behavioral ESD model is developed which reproduces pulse-energy-dependent failure levels and self-heating effects. This modeling methodology can be used for assessment of system robustness even beyond ESD time-domain. The validation of the models is given by representative application examples. Several main challenges of high-voltage ESD design in smart power technologies have been addressed in this work, which can serve as guidance for ESD development and product support in future power semiconductor technologies.