Insulated gate bipolar transistor and preparation method thereof

Abstract

The invention relates to the technical field of power semiconductor chips, and discloses an insulated gate bipolar transistor and a preparation method thereof. The transistor comprises a substrate; acollector layer and a device layer are arranged on the substrate; the projection of the device layer on the substrate comprises at least two opposite side edges, and a set distance is formed between the side edges and the edge of the projection of the collector layer on the substrate; the outer surface of the device layer is coated with a dielectric layer; an emitter bonding metal layer is formedon the side, away from the device layer, of the dielectric layer; and a collector bonding metal layer is arranged on the side, away from the substrate, of the collector layer and located outside the device layer. In the above transistor, when the transistor is electrified, electrons sequentially pass through the emitter bonding metal layer, the device layer, the collector layer and the collector bonding metal layer, current conduction is realized, so that a current passing path does not pass through the substrate, a thicker substrate can be adopted in the transistor to bear an ultrathin devicelayer, an ultrathin thinning process and related complex steps are not needed, and the manufacturing cost and the manufacturing difficulty are reduced.

Description

technical field [0001] The invention relates to the technical field of power semiconductor chips, in particular to an insulated gate bipolar transistor and a preparation method thereof. Background technique [0002] The insulated gate bipolar transistor FS-IGBT (Field Stop Insulated Gate Bipolar Transistor) with an electric field stop structure is the most advanced IGBT device at present. Because it increases the N-type semiconductor layer structure, the electric field distribution of the device is cut off (Field Stop Insulated Gate Bipolar Transistor) Stop), thereby reducing the thickness of the N-type withstand voltage layer, reducing the conduction voltage drop and power loss of the device. Compared with other PT-IGBT and NPT-IGBT structures, its performance has been greatly improved, and it has gradually become the mainstream design in the IGBT field; the structure of FS-IGBT in the prior art is as follows figure 1 As shown, it includes an emitter bonding metal layer 05...

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Problems solved by technology

[0003] However, in terms of process technology, in order to achieve the characteristic of field stop, the thickness of the substrate layer must be ground to a very thin level, which has caused great difficulty in the manufacture of the entire FS-IGBT chip.

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