S340, performing a second phrase front side process.

FIG. 4J shows a cross-section view of the field stop reverse conducting insulated gate bipolar transistor after the step S340 is performed. The second phrase front side process specifically comprises photoetching and etching the oxide dielectric layer 7, forming a contact hole by having a part of the P well 5 and the emitter 6 exposing, filling an emitter metal structure 8 in the contact hole, then forming a passivation layer 9. The silicon oxide layer and the emitter metal structure 8 is covered by the passivation layer 9. The function of the passivation layer 9 is to prevent the surface of the chip from contaminating of the external ions. In the embodiment, the material of the passivation layer 9 is SiN.

S350, forming a plurality of notches in the active region through the back side P-type structure into the field stop layer, wherein the back side metal layer is filled in the plurality of notches.

Referring to FIG. 4K, forming a plurality of notches 11, wherein the back side metal layer is filled in the plurality of notches to form a metal structure extending in the field stop layer, as shown in FIG. 2. In the embodiment, the back side metal layer 12 employs an Al—Ti—Ni—Ag structure.