Junction terminal structure for power device

Abstract

The invention relates to the technical field of power semiconductors, in particular to a junction terminal structure capable of improving the total dose radiation resistance. The junction terminal structure is mainly characterized in that different thicknesses of field oxide layers are arranged on both sides above a field limiting ring, and polycrystalline silicon field plates are arranged on both sides above the field limiting ring; since the thicknesses of the field oxide layers below the polycrystalline silicon field plates are different, a height difference exists in the longitudinal direction of the polycrystalline silicon filed plates on both sides; a structure with a capacitor function is formed by the polycrystalline silicon field plate structures which are formed in a staggered manner and the field oxide layer structure below the polycrystalline silicon field plates, an overlaying effect formed by total dose radiation to an electric field below the field plate on the right side is weakened by redistribution, and thus the voltage endurance capability of a junction terminal after total dose radiation is improved to a certain degree. According to the junction terminal structure disclosed by the invention, the total dose radiation resistance of the device is improved on the premise of not increasing the area of the junction terminal, so that the voltage endurance drop caused by radiation is reduced, and the demands under high-power and complex environment application are met. The junction terminal structure is especially applicable to power semiconductor devices.

Description

technical field [0001] The invention belongs to the technical field of power semiconductors, in particular to a junction terminal structure capable of improving the ability to resist total dose radiation. Background technique [0002] Modern high-voltage power semiconductor devices such as IGBT, VDMOS and other products are more and more widely used in related fields due to their fast switching speed and high operating frequency. Since the development of junction termination technology, a variety of structures, such as field limiting rings, field plates, deep grooves, and junction termination extension technologies have been greatly developed, and great progress has been made in optimizing the surface breakdown characteristics of devices. For the junction termination structure of a general device, it is generally formed by a combination of a field limiting ring and a field plate. The method has a simple structure and is convenient to implement, and can better improve the wi...

AI Technical Summary

Problems solved by technology

However, the withstand voltage capability of the total dose increased by these methods is very limited, and more device area is sacrificed, and the overall structure and applicable conditions are more complicated, resulting in unsatisfactory actual effects.

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