Bidirectional symmetrical TVS diode and manufacturing method thereof

Abstract

The invention relates to a bidirectional symmetrical TVS diode and a manufacturing method thereof. According to the invention, a low-pressure chemical vapor deposition method is used to reduce a thermal process, transverse bidirectional TVS is realized, the performance is stable, and the bidirectional symmetry is consistent. An etching method including a dry method and a wet method is employed, thereby guaranteeing that the silicon in the window is prevented from being over-etched, guaranteeing the good shape and appearance of a window, facilitating the metal coverage, and improving the reliability of a device; a surface dielectric layer uses TEOS silicon dioxide produced by low-pressure chemical vapor deposition to replace silicon dioxide produced by thermal oxidation, so the thermal process in the process is greatly reduced, the production cost is reduced, and the stability of the device is improved. One end of the TVS is connected to the back surface of the chip through the punch-through region, so the area of the chip is saved.

Description

technical field [0001] The invention relates to a TVS diode, in particular to a bidirectional symmetrical TVS diode and a manufacturing method thereof. Background technique [0002] Transient interference of voltage and current is the main cause of damage to electronic circuits and equipment, and often brings incalculable losses to people. These disturbances usually come from the start-stop operation of power equipment, the instability of the AC power grid, lightning interference and static discharge points, etc. Transient interference is almost everywhere and occurs all the time, making people feel hard to guard against. Fortunately, the emergence of a high-efficiency circuit protection device TVS has effectively controlled transient interference. When the two ends of the TVS tube are subjected to an instantaneous high-energy impact, it can suddenly reduce its impedance at a very high speed, and at the same time absorb a large current, and clamp the voltage between its two...

AI Technical Summary

Problems solved by technology

Traditional bipolar TVS has great limitations, the consistency of their bidirectional voltage is difficult to control, and the fluctuations in the process have a great impact on the voltage in both directions

There are also some bidirectional TVS protection circuits composed of multiple packaged separate TVS. The combination of these independent chips results in low integration, large size, and waste of chip area.

Images