Carrier storage type igbt and manufacturing method thereof

Abstract

The invention discloses a carrier storage type IGBT which comprises a drift area, a P type body area, and a hole injection layer. Multiple first and second grooves are arranged alternately. Each of the second trenches is formed by the longitudinal superposition of a bottom trench and a top trench, and a gate dielectric layer and a polysilicon gate are formed in each of the first and two trenches. The bottom trench of the second trench is formed by using isotropic etching after forming the top trench. The bottom trench allows the coverage areas of the side face of the bottom area and the bottom surface of the second trench to be increased. When a device is conducted, a hole storage layer is formed by an N type accumulation layer formed by a drift area surface covered by the side face and bottom surface of the bottom trench. The invention also discloses a manufacturing method of the carrier storage type IGBT. According to the carrier storage type IGBT and the manufacturing method thereof, the storage effect of a hole at the drift area can be enhanced, the pressure drop and anti-latch performance of the IGBT are improved, and breakdown voltage is not sacrificed.

Description

technical field [0001] The invention relates to the field of manufacturing semiconductor integrated circuits, in particular to a carrier storage type IGBT; the invention also relates to a method for manufacturing the carrier storage type IGBT. Background technique [0002] Insulated Gate Bipolar Transistor (IGBT) is a composite fully-controlled voltage-driven power semiconductor device composed of a bipolar transistor (BJT) and an insulated gate field effect transistor (MOSFET). A giant transistor (Giant Transistor, GTR) that can work at high voltage and high current is also a power transistor; IGTB has the advantages of high input impedance of MOSFET and low conduction voltage drop of GTR. It is very suitable for the conversion system with a DC voltage of 600V and above, such as AC motors, frequency converters, switching power supplies, lighting circuits, traction drives and other fields. [0003] Such as figure 1 Shown is a schematic diagram of the existing IGBT structur...

AI Technical Summary

Problems solved by technology

However, under the action of the electric field, part of the holes injected on the back side will be swept out of the drift region by the electric field, as shown by the arrow line 121, and flow out through the contact hole, which is the so-called hole current; the hole current will increase the conduction of the device voltage drop and degrades the device's immunity to latch-up

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