Reverse conducting IGBT (Insulated Gate Bipolar Translator) capable of eliminating voltage turn-back phenomenon

Abstract

The invention discloses a reverse conducting IGBT (Insulated Gate Bipolar Translator) capable of eliminating a voltage turn-back phenomenon, which comprises a semi-cellular structure, and the semi-cellular structure comprises a collector electrode structure, a voltage-withstanding layer structure, an emitter electrode structure and a grid electrode structure, the collector structure is located at one end of the voltage-withstanding layer structure, and the emitter structure and the gate structure are located at two sides of the other end of the voltage-withstanding layer structure; wherein the collector structure comprises a P + collector region, an N + collector region, an N-type buffer layer, a P + conductive material, collector metal, an N-type conductive material and floating metal; one side of the N-type buffer layer is connected to the voltage withstanding layer structure, one side of the P + collector region and one side of the N + collector region are connected to the other side of the N-type buffer layer, a gap is formed between the P + collector region and the N + collector region, and collector metal is arranged on the other side of the P + collector region; on the basis of a conventional reverse conducting IGBT structure, the snapback phenomenon is eliminated by optimizing and improving the collector electrode structure, and the reverse conducting current is more uniform.

Description

technical field [0001] The present invention relates to the field of power semiconductor technology, and more particularly to a reverse conduction IGBT which eliminates the phenomenon of voltage foldback. Background technique [0002] like Figure 3-4 The schematic diagram of the structure and equivalent circuit of the conventional reverse conduction IGBT shown, when the conventional reverse conduction IGBT is conducting forward, the N+ collector region (12) is turned on first. At this time, the device works in the unipolar conduction mode and is turned on. The resistance is relatively large. Due to the parasitic resistance of the N-type buffer layer (13), with the increase of the anode voltage, the anode current will produce a voltage drop on the parasitic resistance. When the potential difference between this voltage drop and the P+ collector region (11) is greater than 0.7 When V, the PN junction of the P+ collector region (13) / N-type buffer layer (13) is turned on, the...

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Problems solved by technology

[0002] like Figure 3-4 The conventional reverse conduction IGBT structure and equivalent circuit schematic diagram shown, when the traditional reverse conduction IGBT conducts forward, the N+ collector region (12) conducts first, and the device works in the unipolar conduction mode at this time, the conduction The resistance is relatively large. Due to the parasitic resistance of the N-type buffer layer (13), as the anode voltage increases, the anode current will generate a voltage drop on the parasitic resistance. When the potential difference between this voltage drop and the P+ collector region (11) is greater than 0.7 At V, the PN junction of the P+ collector region (13) / N-type buffer layer (13) is turned on, and the device enters a bipolar conduction mode with low on-resistance, and a sharp drop in on-resistance will cause voltage foldback , in order to alleviate this phenomenon, the length of the P+ collector region (11) of the conventional reverse conduction type IGBT is often designed to be very long, but this will cause the length of the N+ collector region (12) to be relatively short, and the reverse conduction type IGBT device reverse conductivity When on, the P+ body contact region (33), P-type well region (31), N-type drift region (21), N-type buffer layer (13) and N+ collector region (12) form a diode conduction current, at this time If the length of the N+ collector region (12) is short, it will lead to uneven distribution of reverse conduction current, which will affect device performance and system reliability

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