A soft and fast recovery diode and its manufacturing method

Abstract

The invention relates to a soft fast recovery diode and a manufacturing method thereof. The diode comprises an N type intrinsic region, a back N<+> buffer region, an anode metal layer and a cathode metal layer, wherein the back N<+> buffer region is formed on the back face of the N type intrinsic region; a P type emitting region is formed between the front face of the N type intrinsic region and the anode metal layer; mask oxide layers are formed symmetrically at the two ends of the anode metal layer; a P type high-resistance region is formed on the boundary of an active region; a P<+> ohmic contact layer is formed in the center of the active region; an overall lifetime control region is formed on the entire diode, and covers all structural layers of the diode; a localized lifetime control layer is positioned close to the P<+> ohmic contact layer in the P type emitting region along the axial direction of the diode; the localized lifetime control layer is positioned in a plane constructed by the P type emitting region and the P type high-resistance region along a direction which is vertical to the axial direction of the diode. The soft fast recovery characteristic of a device is realized by adopting an overall-localized lifetime control way; by arranging the high-resistance region, the snow slide resistance of the device is improved.

Description

technical field [0001] The invention relates to a semiconductor power device, in particular to a soft fast recovery diode and a manufacturing method thereof. Background technique [0002] Single or multiple fast recovery diode (FRD) chips are anti-parallel connected to insulated gate bipolar transistor (IGBT) chips and packaged into IGBT modules, collectively referred to as IGBT devices, which are widely used in power systems with voltages of 1200V-6500V, locomotive traction, etc. high voltage field. As the withstand voltage of the device increases, the FRD chip with the characteristics of soft and fast recovery, low shock and high avalanche tolerance is called a soft and fast recovery diode in the present invention, and its importance becomes more and more prominent. [0003] The working process of FRD is the process of carrier (electron and hole) injection and extraction, and the advantages of soft and fast recovery diodes are reflected in the reverse recovery work. When...

AI Technical Summary

Problems solved by technology

But for the traditional FRD structure, if t rr If it is reduced to the order of tens to hundreds of ns, the carrier lifetime must be reduced to a minimum, and the internal defects of the chip will increase, which will lead to large reverse leakage, poor terminal reliability, and softness factor. The risk of small and increased vibration; at the same time, existing research shows that the defects produced by electron irradiation will be eliminated in high temperature and long-term work, degrading the performance of the device

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