ESD Design and Analysis by Drain Electrode-Embedded Horizontal Schottky Elements for HV nLDMOSs

• Published in: Electronics (Basel) Vol. 10; no. 2; p. 178
• Main Authors: Hong, Shi-Zhe, Chen, Shen-Li
• Format: Journal Article
• Language: English
• Published: 15.01.2021
• ISSN: 2079-9292; 2079-9292
• DOI: 10.3390/electronics10020178

Electrostatic discharge (ESD) events can severely damage miniature components. Therefore, ESD protection is critical in integrated circuits. In this study, drain-electrode-embedded horizontal Schottky diode contact modulation and Schottky length reduction modulation were performed on a high-voltage 60-V n-channel laterally diffused metal-oxide–semiconductor transistor (nLDMOS) element. The effect of the on-voltage characteristics of cascade Schottky diodes on ESD protection was investigated. By using a transmission-line pulse tester, the trigger voltage, holding voltage, and secondary breakdown current (It2) of the nLDMOS element were determined using the I–V characteristic. As the N+ area was gradually replaced by the parasitic Schottky area at the drain electrode, an equivalent circuit of series Schottky diodes formed, which increased the on-resistance. The larger the Schottky area was the higher the It2 value was. This characteristic can considerably improve the ESD immunity of nLDMOS components (highest improvement of 104%). This is a good strategy for improving ESD reliability without increasing the production steps and fabrication cost.