RC-IGBT Body Layer Layout for Reverse Recovery and On-Voltage

The patent applies local quality by forming a lifetime control layer only in the diode part's drift layer below the p-body layer, while intentionally excluding the IGBT part from this modification. This localized approach allows the diode to achieve improved reverse recovery characteristics through reduced carrier lifetime in the drift layer, while the IGBT maintains its original on-voltage characteristics since its drift layer remains unmodified. The selective formation of the lifetime control layer creates different structural qualities in different regions of the same semiconductor device.

The patent applies segmentation by dividing the semiconductor device into distinct IGBT and diode regions with different structural characteristics. The body layer in the diode part is formed shallower than in the IGBT part, creating spatial separation that enables selective lifetime control. This segmentation allows subsequent ion implantation to affect only the diode region's drift layer, achieving reverse recovery improvement without requiring complex metal mask patterns to protect the IGBT region during fabrication.

The patent applies preliminary action by forming the body layers at different depths early in the fabrication process, before any lifetime control layer formation steps. This preliminary structural differentiation establishes the foundation for selective ion implantation in later stages. By pre-configuring the body layer depth variation, the patent enables subsequent drift layer modification to automatically affect only the diode part, converting what would otherwise require complex masking into a simpler process that relies on the pre-established structural asymmetry.