Superjunction IGBT with cutoff reverse conduction field and manufacturing method thereof

Abstract

The invention provides a superjunction IGBT with a cutoff reverse conduction field. A second semiconductor material is implanted in a first semiconductor substrate to form a reverse conducting structure with the first semiconductor substrate. A field stopping layer and a second semiconductor material epitaxial layer with a low doping concentration are successively stacked on the upper surface of the first semiconductor substrate. A first semiconductor material and a second semiconductor material having the same concentration are implanted in the second semiconductor material epitaxial layer with the low doping concentration. The first semiconductor material and the second semiconductor material alternately form a superjunction structure multiple times along a plane wherein the epitaxial layer is located. The invention also provides a method for manufacturing the IGBT. The superjunction IGBT with a cutoff reverse conduction field and its manufacturing method can effectively reduce the saturation voltage drop of the IGBT and obtain high power density, can make the IGBT thinner and smaller, integrate a reverse conducting diode, and reduce manufacturing cost.

Description

technical field [0001] The present invention relates to transistors, and more particularly to insulated gate bipolar transistors. Background technique [0002] IGBT (Insulated Gate Bipolar Transistor) is a composite fully-controlled-voltage-driven-power semiconductor device composed of BJT (Bipolar Junction Transistor) and MOS (Insulated Gate Field Effect K-tube), with MOSFET The advantages of high input impedance and low conduction voltage drop of BJT. It is widely used in DC 600V and above conversion systems such as AC motors, inverters, lighting circuits, and traction drives. [0003] The IGBT is essentially a field effect transistor, which is very close to the Power MOSFET in terms of structure, and a P+ layer is added to the drain electrode on the back. In this way, a forward-biased PN junction is formed at the drain end, which does not affect conduction but increases the hole injection effect. Its characteristics are similar to BJT with two types of carriers particip...

AI Technical Summary

Problems solved by technology

[0005] At present, the saturation voltage drop of IGBTs on the market is relatively large and the power density is low. In the application process, a reverse conduction diode needs to be connected in parallel.