Terminal of power semiconductor and manufacturing method of terminal

Abstract

The invention provides a terminal of a power semiconductor and a manufacturing method of the terminal. The power semiconductor comprises a first semiconductor layer of a first conduction type; the first semiconductor layer contains an active region of a well region doped with a second conduction type; the terminal is positioned in the first semiconductor layer, and comprises a junction terminal expansion region adjacent to the active region and doped with a second conduction type; the doping thickness of the junction terminal expansion region increases along with the increase of the distance to the active region; and the doping concentration of the junction terminal expansion region decreases along with the increase of the distance to the active region. In the terminal structure of the invention, the resistivity of the junction terminal expansion increases along with the decrease of the doping concentration; and the cross sectional area within unit length increases along with the increase of the doping thickness, thus relieving the resistance raising caused by the degression of the doping concentration, leading that the potential distribution of the terminal is even, effectively avoiding the premature breakdown from occurring locally, and improving the tolerable voltage of the terminal.

Description

technical field [0001] The invention relates to a terminal structure of a semiconductor device, in particular to a terminal of a power semiconductor device and a manufacturing method thereof. Background technique [0002] Due to the junction bending phenomenon, the terminals of power semiconductor devices often suffer from premature breakdown. Therefore, the design of the terminal protection structure has become an important part of the optimal design of power semiconductor devices, especially high-voltage and high-power devices. [0003] Currently, the more common termination protection structures include field rings, field plates, junction termination extensions (JTE), bevels, trenches, and so on. It is difficult to realize the oblique angle and trench structure, and the field ring and field plate consume a large area, which reduces the utilization rate of the silicon wafer and is greatly affected by the interface charge. Figure 4 It is a schematic diagram of a terminal ...

AI Technical Summary

Problems solved by technology

The analysis shows that the simultaneous effect of decreasing junction depth and decreasing doping concentration will cause the resistance of JTE to increase rapidly outward along the main junction, which is not conducive to the effective transfer of potential, resulting in the sharing of too high potential near the main junction, and the electric field If it is too high, it will break down prematurely and fail to achieve the purpose of effective protection

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