Chip of reverse blocking IGBT and manufacturing method

Abstract

The invention relates to a chip of a reverse blocking IGBT and a manufacturing method. According to the chip and the manufacturing method, hole grooves are formed in the edge of the chip to make contact with a collector P+ area on the back of the chip; and by adoption of physical gas deposition, the chip is put in gas which is full of boron ions to ensure that the boron ions are transversely diffused along the inner walls of the hole grooves until diffusion knots between the hole grooves make contact so as to form a diffusion and isolation area around a terminal area. Different from the conventional reverse blocking IGBT, the method adopts a diffusion method to manufacture the isolation area, so that the diffusion time is short, the operation is not influenced by the thickness of a substrate, the usable area of the isolation area is few and the chip area utilization rate is high. The bottoms of the hole grooves make contact with the collector P+ area on the back, so that the difficultythat the bottom of the diffusion and isolation area is difficult to make contact with the collector on the back as the substrate of a high-voltage device is relatively thick, and the diffusion knotsbetween the hole grooves make contact to form the overall diffusion P+ area so that the terminal area of the chip is isolated from the edge of the chip and then the edge of the chip is avoided from leakage current generation.

Description

Technical field: [0001] The invention relates to the structure of a power semiconductor device in the field of semiconductor technology, and the design of the structure design of the reverse resistance IGBT terminal isolation region. Background technique [0002] Conventional IGBT in order to compromise the on-state voltage drop V on and turn-off loss E off , typically with a buffer layer for smaller V on and E off , because the doping concentration of the buffer layer and the collector layer is very high, and the edge of the chip will cause a large leakage current due to lattice damage and stress, so the conventional IGBT does not have reverse blocking capability. The anti-resistance IGBT adopts the traditional non-punch-through (NPT) structure, and at the same time, it has been improved on the back and side, and an effective edge isolation area P+ is designed at the edge of the chip, so that the edge isolation area P+ and the back P+ area are short-circuited. Avoid the...

AI Technical Summary

Problems solved by technology

For the structural design of the traditional reverse resistance IGBT edge isolation region, see Figure 4A , using this diffusion isolation terminal design, the P+ isolation region is in contact with the bottom P+ is the difficulty of the entire structural design. It is easier to realize the low-voltage reverse resistance IGBT with a thinner substrate, but for higher withstand voltage and thicker substrate For high-voltage devices, it is more difficult to realize

The substrate of the high-voltage reverse resistance IGBT is thick and requires a long diffusion time. The P+ isolation area can be combined with the back P+. Due to the existence of lateral diffusion, the diffusion area of ​​the P+ isolation area is very wide, resulting in a large waste of chip terminal area.

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