Transient voltage suppressor and manufacturing method thereof

Abstract

The invention discloses a transient voltage suppressor and a manufacturing method thereof. The transient voltage suppressor includes: a semiconductor substrate and a second epitaxial layer arranged ona first surface of the semiconductor substrate; a first buried layer extending to the semiconductor substrate; a second buried layer, wherein a first part of the second buried layer extends to the semiconductor substrate, and the second part of the second buried layer extends to the first buried layer; a first isolation region extending to the second epitaxial layer so as to limit a first isolation island and a second isolation island; a second isolation region extending to the second epitaxial layer, wherein a first part of the second isolation region limits a third isolation island in the first isolation island, and a second part of the second isolation region is connected to the first part of the second buried layer; a first well region, wherein a part of the first well region extendsto the third isolation island, and the other part of the first well region is connected to the first buried layer through the first isolation region; and a second well region extending to the second isolation island, and electrically connected to the first part of the first well region. The transient voltage suppressor has a bidirectional transient voltage suppressing function, is low in capacitance, is small in size, is easy to manufacture, and can lead electrodes from a front surface and a back surface.

Description

technical field [0001] The present invention relates to the technical field of semiconductor microelectronics, and more specifically, to a transient voltage suppressor and a manufacturing method thereof. Background technique [0002] Transient Voltage Suppressor (TVS) is a high-efficiency circuit protection device that is commonly used at present. Its appearance is the same as that of ordinary diodes, but its special structure and process design enable it to absorb waves up to several thousand watts. surge power. The working mechanism of the transient voltage suppressor is: under reverse application conditions, when the transient voltage suppressor is subjected to a high-energy large pulse, its working impedance will quickly drop to an extremely low conduction value, thereby allowing large current flow through, while clamping the voltage at a predetermined level, the general response time is only 10 -12 seconds, so it can effectively protect the precision components in the...

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Problems solved by technology

like Figure 2c As shown, since two chips need to be placed on the base island in the bidirectional transient voltage suppressor, it is easy to cause the probability of packaging defects to increase, so that the cost of chip placement is relatively high; during the packaging process, the two A metal wire needs to be punched at each channel end, which also increases the cost; at the same time, since the integrated package of multiple chips requires a large space, the size of the entire bidirectional transient voltage suppressor is large, which is not suitable for smaller packages.

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