High voltage electrostatic protection structure

Abstract

The invention discloses a high-voltage electrostatic protection structure. According to the high-voltage electrostatic protection structure, an N type LDMOS is integrally arranged in an N type buried layer on a silicon substrate; an active area at the right side of a polysilicon gate of the LDMOS device is a drain area of the device, and an N+ type injection area, an N- injection area and a high-voltage N well are located below the drain area; an active region at the left side of the polysilicon gate is a source area of the device, and an N+ type injection area is located below the source area, and a first P type active area which is adjacent to a field oxygen area is arranged at the left side of the N+ type injection area in an isolation manner, and a second P type active area which is adjacent to a field oxygen area is arranged at the left side of the first P type active area in an isolation manner. With the high-voltage electrostatic protection structure of the invention adopted, the trigger voltage of the LDMOS structure can be effectively reduced, and improvement of the uniform conduction ability of the LDMOS which is in interdigital arrangement can be benefitted, and overall electrostatic protection ability of the high-voltage electrostatic protection structure can be improved.

Description

technical field [0001] The invention relates to the field of integrated circuit manufacturing, in particular to a high-voltage electrostatic protection structure. Background technique [0002] Electrostatic discharge (ESD) damage to electronic products has always been a problem that is not easy to solve. For high-voltage processes, electrostatic protection devices not only need to meet the requirements that the withstand voltage is greater than the power supply voltage, but their electrostatic trigger voltage also needs to be lower than the damage of the protected device. Voltage is fine. Such as figure 1 As shown, the high-voltage NLDMOS structure usually used for electrostatic protection is under the occurrence of static electricity. After the ESD positive charge enters the drain of the structure from the input and output pads, the potential of the N-diffusion region is raised, and an avalanche breakdown occurs, and the breakdown current passes through The P+ diffusion r...

AI Technical Summary

Problems solved by technology

The triode is turned on mainly by the junction breakdown between the N-diffusion region and the high-voltage P well. The trigger voltage is generally relatively high, and it is not easy to play a protective role.

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