FRD structure and manufacturing method and application thereof

Abstract

The invention provides an FRD structure and a manufacturing method and application thereof. Wherein the FRD structure comprises a substrate and a terminal annular field oxide layer covering the substrate, the terminal annular field oxide layer is annularly arranged along the periphery of the substrate, and a source region corresponding to the middle position of the substrate is defined by the terminal annular field oxide layer; the FRD structure further comprises a P-well region and a plurality of P + well regions, the P-well region covers the substrate and is located in the source region, the P + well regions cover the P-well region and are embedded in the P-well region, the P + well regions are spaced from one another to form at least one discharge channel, and the two opposite ends of the discharge channel are connected with the terminal annular field oxide layer; and the discharge channel is used for guiding the avalanche current of the FRD structure to the middle position of the source region. According to the FRD structure, the avalanche current mainly flows to the middle position of the source region through the discharge channel, so that the avalanche current cannot be concentrated on the edge of the chip, the heat dissipation area of the chip is increased, heat accumulation and local hot spots are not easy to form, and the avalanche tolerance and reliability of the FRD structure can be effectively improved.

Description

【Technical field】 [0001] The present application relates to the technical field of power electronic devices, in particular to a FRD structure and its manufacturing method and application. 【Background technique】 [0002] FRD (Fast Recovery Diode, fast recovery diode) is a semiconductor diode with good switching characteristics and short reverse recovery time. It is mainly used in switching power supply, PWM (Pulse Width Modulation, pulse width modulation) pulse width modulator And inverter and other electronic circuits, and used as high-frequency rectifier diodes, freewheeling diodes or damping diodes. The internal structure of FRD is different from ordinary PN junction diodes. It belongs to PIN junction diodes, that is, the base region I is added between the P-type silicon material and the N-type silicon material to form a PIN silicon chip; Thin, so the reverse recovery charge of FRD is smaller, the reverse recovery time is shorter, the forward voltage drop is lower, and th...

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