A grooved anode FRD with two-pole Schottky control and its manufacturing method

Abstract

The invention relates to a groove-type anode fast recovery diode with bipolar Schottky control and its manufacturing method, comprising: a cathode metal, an N-type intrinsic region above the cathode metal, and an N-type intrinsic region above the N-type intrinsic region The anode metal is provided with lightly doped N-type regions and heavily doped N-type regions spaced apart from each other on the cathode metal, the bottom of the lightly doped N-type region is in Schottky contact with the cathode metal, and in the N-type intrinsic region There are heavily doped P-type regions and lightly doped P-type regions spaced apart from the anode metal, and the upper surface of the heavily doped P-type region is lower than the upper surface of the lightly doped P-type region, forming a concave In the slot-type anode area, the lightly doped P-type area and the anode metal are in Schottky contact. The manufacturing method of the two-pole Schottky-controlled recess type anode fast recovery diode is characterized in that the Schottky contacts on the surface of the anode and the side wall can be formed simultaneously by one-step etching.

Description

technical field [0001] The invention mainly relates to the technical field of power semiconductor devices, in particular to a groove type anode fast recovery diode with bipolar Schottky control. Background technique [0002] In various frequency conversion circuits and power electronic systems, whether the main circuit in the circuit is a thyristor with commutation shutdown or a new type of switching device with self-shutoff capability, it is necessary to connect it in parallel and provide freewheeling. The diode of the loop (later referred to as FRD). As the frequency and performance of power electronic devices in these circuit systems continue to increase, in order to match their turn-off capabilities, their FRDs must have fast turn-on and turn-off capabilities, that is, have a lower forward conduction voltage V F and extremely short reverse recovery time. At the same time, in order to improve the energy efficiency and reliability of the system, its FRD must have a small...

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Problems solved by technology

It is also because of this that the traditional PiN diode has a large amount of minority carriers stored in the intrinsic region during the forward conduction period, so that during the reverse recovery period, the extraction speed of the minority carriers in the intrinsic region is slow, and finally It leads to a longer reverse recovery time, which seriously increases the power consumption of the system circuit and limits the improvement of the system operating frequency.

In order to improve the switching speed of FRD, lifetime control technology is often used, such as metal impurity doping and electron irradiation technology to reduce the lifetime of minority carriers in the intrinsic region. Using this technology can effectively shorten the reverse recovery of FRD time, increase the switching speed, but at the same time, it will also cause a high reverse leakage current, which seriously affects the normal logic function of the circuit system. The oscillating current and voltage will seriously threaten the reliability of the device

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