Reverse-Blocking IGBT

Abstract

A method of manufacturing a reverse-blocking IGBT (insulated gate bipolar transistor) includes forming a plurality of IGBT cells in a device region of a semiconductor substrate, forming a reverse-blocking edge termination structure in a periphery region of the semiconductor substrate which surrounds the device region, etching one or more trenches in the periphery region between the reverse-blocking edge termination structure and a kerf region of the semiconductor substrate, depositing a p-type dopant source which at least partly fills the one or more trenches and diffusing p-type dopants fromthe p-type dopant source into semiconductor material surrounding the one or more trenches, so as to form a continuous p-type doped region in the periphery region which extends from a top surface of the semiconductor substrate to a bottom surface of the semiconductor substrate after thinning of the semiconductor substrate at the bottom surface.

Description

technical field [0001] The present application relates to reverse blocking IGBTs, and more particularly to reverse blocking IGBTs with reduced chip area. Background technique [0002] Reverse blocking IGBTs (Insulated Gate Bipolar Transistors) can be achieved by adding minor changes to the structure of a standard IGBT in order to make the device tolerant of reverse voltages. Reverse blocking capability is required in various applications such as current source inverters, resonant circuits, bidirectional switches, matrix converters, and the like. [0003] Reverse blocking IGBTs differ from forward only blocking IGBTs in that the p-n junction at the backside of the die is protected from the cut edge of the die by a p-type region. Conventionally, the p-type region is formed by a very deep dopant diffusion process around the perimeter of the die (chip). The region of deep diffusion surrounds the perimeter of the die and occupies the full thickness of the die. Under reverse bl...

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Problems solved by technology

Additionally, a high thermal budget is required, further limiting integration options

In addition, the active side area of ​​the die is consumed by the deep dopant diffusion process, which increases the die size and can only be cut by cutting the semiconductor die in the kerf area (i.e., the semiconductor wafer by, for example, a saw blade or a laser). regions that are singulated (physically separated) from each other) to partially offset the diffusion process

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