A Transient Voltage Suppressor Based on Zener Diode

Abstract

The invention discloses a transient voltage suppressor based on a Zener diode, which comprises an N substrate layer, wherein a first P+ epitaxial region, a second P+ epitaxial region, an N+ buried layer, a four P+ epitaxial region and a fifth P+ epitaxial region are sequentially arranged on the N substrate layer from left to right; a first P- well and a third P- well are respectively arranged on the second P+ epitaxial region and the fourth P+ epitaxial region; a third P+ epitaxial region, a second P- well and a third N+ active injection region are sequentially arranged on the N+ buried layerfrom bottom to top; a first P+ active injection region and a fourth P+ active injection region are respectively arranged on the first P+ epitaxial region and the five P+ epitaxial region; and an N+ active injection region and a P+ active injection area are respectively arranged on the first P-well and the third P-well in a corresponding manner. According to the transient voltage suppressor, the parasitic capacitance of the TVS (Transient Voltage Suppressor) is further reduced by adopting a composite structure of the Zener diode and a low capacity diode; and therefore, the transient voltage suppressor can be widely applied to certain portable equipment and high-speed interfaces for static electricity protection.

Description

technical field [0001] The invention belongs to the technical field of electrostatic protection for integrated circuits, and in particular relates to a transient voltage suppressor based on Zener diodes. Background technique [0002] With the rapid development of electronic information technology, the current semiconductor devices tend to be miniaturized, high-density and multi-functional, especially for applications such as fashion consumer electronics and portable products that have strict requirements on the motherboard area, they are vulnerable to electrostatic discharge (ESD) )Impact. Static electricity exists all the time and everywhere. In the 1960s, with the emergence of MOS devices that are very sensitive to static electricity, the problem of static electricity also appeared. In the 1970s, the problem of static electricity became more and more serious. The density of the circuit is getting bigger and bigger. On the one hand, the thickness of the silicon dioxide fil...

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Problems solved by technology

[0008] However, most of the diode structures in traditional TVS are implanted on the P substrate or on the P epitaxy to form a PN junction, relying on a large PN junction area to carry the large ESD current, or injecting P+ on the N substrate or N epitaxy to form a PN junction. Conclusion; At present, traditional TVS is mainly used in portable electronic products such as mobile phones, MP3 and digital cameras. Due to the slow data transmission speed of these products, the requirements for the parasitic capacitance of TVS are not high, and generally allow (30 ~ 100)pF However, some current high-end digital products basically use high-speed transmission interfaces such as USB2.0, USB3.0, HDMI, etc., such as USB3.0, and the data transmission rate reaches 600MBps, so the parasitic capacitance of TVS is extremely demanding. It must be lower than 3.5pF or even lower, so the traditional TVS with large capacitance value applied to the high-speed transmission interface will affect the signal integrity of the entire system, lose the performance of ESD protection, and can no longer meet this high-speed requirement

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