IGBT device and preparation method thereof

The invention discloses an IGBT (Insulated Gate Bipolar Translator) device and a preparation method thereof. The device comprises a substrate; the super junction structure layer comprises a first epitaxial layer, a first conductive type epitaxial layer and a second conductive type epitaxial layer; the second conductive type epitaxial layers of the adjacent super junction structure layers are in direct contact; a first conductive type well region, a second conductive type emitter region, a gate trench and an emitter trench are arranged on one side, far away from the multi-layer super junction structure layer, of the second epitaxial layer; the trench gate structure comprises a first dielectric layer, a gate and a second dielectric layer; a collector electrode; an emitter; and a gate conductive layer. According to the technical scheme of the embodiment of the invention, the super junction structure formed by the first conductive type epitaxial layer and the second conductive type epitaxial layer ensures the vol