To reduce or transfer the harm of ESD to the microelectronics field, it is first necessary to have a deep understanding of the relevant mechanisms. There are generally two modes of failure caused by ESD:

1、 Hard failure, material damage or destruction;

2、 Soft failure, temporary changes in logical functionality, (potential failure, time-dependent failure).

Currently, potential failure remains the most controversial type of ESD damage. There are two views on potential failure: some people believe that potential failure is possible, but with a very low probability of occurrence; Some people believe that the probability of ESD causing damage to semiconductor devices and immediate device failure is about 10%, so 90% of devices have the potential for failure.

The factors that cause these failures can be divided into thermal failure and electrical failure. Thermal failure refers to the generation of large currents ranging from a few amperes to several tens of amperes locally during an ESD event. Although the duration may range from a few nanoseconds to several hundred nanoseconds, the large amount of heat generated can cause melting of local metal interconnects or the appearance of heat spots on the chip, resulting in secondary breakdown. Electrical failure refers to the electric field strength formed by the voltage applied to the gate oxide layer being greater than its dielectric strength, resulting in dielectric breakdown or surface breakdown.

Regarding the above ESD damage mechanisms, ESD protection can be implemented from three different levels:

A. Prevent the generation of static electricity from the source, reduce or even eliminate the accumulation of static electricity;

B. Off chip ESD protection, which uses peripheral devices to protect the chip from ESD damage;

C. On chip ESD protection refers to the integration of ESD protection circuits onto a chip to enhance its own protection capability.

So, how to control the generation and accumulation of static charges, prevent the formation of dangerous static power sources, and use substances with low static electricity to reduce the degree of harm caused by static electricity in specific locations, adopt comprehensive protection technologies, and prevent ESD energy coupling.