A power device junction terminal structure

Abstract

The invention relates to the technical field of power semiconductors, in particular to a junction terminal structure capable of improving the ability to resist total dose radiation. In the present invention, field oxide layers with different thicknesses are mainly arranged on both sides above the field limiting ring, and there are polysilicon field plates on both sides above the ring. Since there is a difference in the thickness of the field oxide layer below the polysilicon field plate, the polysilicon field plates on both sides are vertically There is a height difference, and the staggered polysilicon field plate structure and the field oxide layer structure below form a capacitive structure, and the redistribution weakens the superimposed effect of the electric field formed under the right field plate due to the total dose irradiation, so that The voltage resistance of the junction terminal after the total dose irradiation is improved to a certain extent. On the premise of not increasing the terminal area of ​​the junction, the invention improves the anti-total dose radiation capability of the device, reduces the withstand voltage drop caused by radiation, and satisfies the requirements of high-power and complex environment applications. The invention is particularly applicable to power semiconductor devices.

Description

Technical field [0001] The invention belongs to the technical field of power semiconductors, and particularly relates to a junction terminal structure capable of improving the ability to resist total dose irradiation. Background technique [0002] Modern high-voltage power semiconductor devices such as IGBT, VDMOS and other products, due to their fast switching speed and high operating frequency, are more and more widely used in related fields. Since the development of junction termination technology, a variety of structures, such as field limiting loops, field plates, deep trenches, 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 general devices, it is generally formed by a combination of field limiting loops and field plates. The method is simple in structure, convenient to implement, and can better improve the...

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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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