Cell Design Consideration in SiC Planar IGBT and Proposal of New SiC IGBT With Improved Performance Trade-Off

oleh: Meng Zhang, Yamin Zhang, Baikui Li, Shiwei Feng, Mengyuan Hua, Xi Tang, Jin Wei, Kevin J. Chen

Format: Article
Diterbitkan: IEEE 2023-01-01

Deskripsi

In silicon carbide (SiC) planar insulated-gate bipolar transistor (IGBT), a large distance between neighboring p-bodies is beneficial to enhance the on-state conductivity modulation, but will expose the gate oxide to high electric field in off-state. With p-bodies placed closer, the gate oxide field is reduced, but the conductivity modulation is suppressed. In this work, a new SiC planar IGBT with oxide shield is proposed and studied by TCAD simulations. The proposed SiC IGBT achieves improved trade-off between on-state voltage drop <inline-formula> <tex-math notation="LaTeX">$(V_{\mathrm{ ON}})$ </tex-math></inline-formula> and maximum gate oxide electric field <inline-formula> <tex-math notation="LaTeX">$(E_{\text {ox-m}})$ </tex-math></inline-formula>. When a quite larger distance between neighboring p-bodies is adopted in the proposed SiC IGBT, a low <inline-formula> <tex-math notation="LaTeX">$V_{\mathrm{ ON}}$ </tex-math></inline-formula> is obtained, while the <inline-formula> <tex-math notation="LaTeX">$E_{\text {ox-m}}$ </tex-math></inline-formula> can be kept at a small value with the oxide shielding structures protecting the gate oxide. Switching characteristics are also studied, and the proposed SiC-IGBT delivers much better trade-off between turn-off energy loss <inline-formula> <tex-math notation="LaTeX">$(E_{\mathrm{ OFF}})$ </tex-math></inline-formula> and <inline-formula> <tex-math notation="LaTeX">$V_{\mathrm{ ON}}$ </tex-math></inline-formula> than the conventional SiC planar IGBT.