Silicon carbide MPS diode with high surge current

Abstract

The invention discloses a silicon carbide MPS diode with high surge current, which is formed by sequentially stacking a cathode ohmic contact electrode, a silicon carbide N + substrate and a silicon carbide N-epitaxial layer, a plurality of P + injection regions are arranged on the silicon carbide N-epitaxial layer at intervals, ohmic contact electrodes are arranged on the P + injection regions, and the ohmic contact electrodes are arranged on the silicon carbide N + substrate. Gaps between the ohmic contact electrodes are filled with Schottky contact electrodes, and bipolar transmission layers are arranged on the two sides of the silicon carbide N-epitaxial layer. According to the MPS diode, due to the existence of the variously doped bipolar transmission layer, the PN junction conduction voltage of the MPS diode is reduced, the diode can enter a bipolar working state in advance under a lower current, a conductivity modulation effect is generated, the conduction resistance of the diode is reduced, the chip temperature of the diode under a large current is reduced, and the performance of the MPS diode is improved. Therefore, the surge current resistance of the diode is improved, and the reverse breakdown voltage of the MPS diode can also be improved.

Description

technical field [0001] The invention relates to the technical field of diodes. Background technique [0002] Silicon carbide (SiC), a wide bandgap semiconductor material, is an ideal material for preparing high-voltage power electronic devices. Compared with Si materials, SiC materials have a higher breakdown electric field strength (4×10 6 V / cm), high carrier saturation drift velocity (2×10 7 cm / s), high thermal conductivity, and good thermal stability, so it is especially suitable for high-power, high-pressure, and high-temperature application scenarios. SiC Junction Barrier Schottky Diodes (JBS), as the earliest commercialized product in SiC power devices, now occupy the largest number of market shares. Through the potential barrier formed by the contact between SiC semiconductor and metal, the rectification effect of conducting in one direction and blocking in one direction is realized. The advantages of JBS diodes in power systems are the advantages of low on-resista...

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Problems solved by technology

In order to ensure that the working current under normal operation meets the requirements, usually the PN junction area accounts for a small proportion of the total chip area. Due to the small proportion of the PN junction area to the total chip area, the PN junction conduction voltage is large, and the PN junction is under the impact of surge current. The junction is not conducting, causing the diode to fail prematurely

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