Numerical Analysis of an Ultralow Switching Loss IGBT With an Inner Primary Blocking Junction

Abstract

To reduce switching loss, an insulated gate bipolar transistor (IGBT) with an inner primary blocking junction (IPBJ) is proposed and investigated. By inserting a P-drift between the N-drift and carrier storage (CS) layer, a primary blocking junction ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${J}_{\text {PB}}{)}$ </tex-math></inline-formula> of the P-drift/N-drift junction and a secondary blocking junction ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${J}_{\text {SB}}{)}$ </tex-math></inline-formula> of the P body/CS layer junction are formed. <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${J}_{\text {PB}}$ </tex-math></inline-formula> is in the inner of the drift region and supports most of the blocking voltage. This reduces the electric potential in the CS layer and hole density in the hole inversion layer around the trench gate during the turn-on transient. Consequently, its turn-on loss ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${E}_{\text {on}}{)}$ </tex-math></inline-formula> and electromagnetic interference (EMI) noise tradeoff relationship is improved. <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${J}_{\text {PB}}$ </tex-math></inline-formula> is forward-biased by the ON-state excess hole in the P-drift. Thus, no electric field ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${E}$ </tex-math></inline-formula> -field) builds in <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${J}_{\text {PB}}$ </tex-math></inline-formula> until the excess hole in the P-drift is swept out by the <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${E}$ </tex-math></inline-formula> -field extending from the reverse-biased <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${J}_{\text {SB}}$ </tex-math></inline-formula> to <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${J}_{\text {PB}}$ </tex-math></inline-formula> . Hence, with almost no excess hole in the P-drift, the <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${E}$ </tex-math></inline-formula> -field in <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${J}_{\text {PB}}$ </tex-math></inline-formula> can build fast in both the P-drift and N-drift directions. This reduces the collector voltage rising time, as well as turn-off loss ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${E}_{\text {off}}{)}$ </tex-math></inline-formula> . Simulation results show that, compared with the state-of-the-art carrier-stored trench-gate bipolar transistor (CSTBT), the proposed 650-V class silicon IPBJ-IGBT reduces <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${E}_{\text {off}}$ </tex-math></inline-formula> by 79.7% with the same ON-state voltage ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${V}_{\text {on}}{)}$ </tex-math></inline-formula> and reduces <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${E}_{\text {on}}$ </tex-math></inline-formula> by 77.9% with the same current overshoot ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${I}_{\text {peak}}{)}$ </tex-math></inline-formula> . Besides, with its <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${E}$ </tex-math></inline-formula> -field and electric potential distribution optimized, the IPBJ-IGBT also improves its blocking characteristic, short-circuit withstand capability, and unclamped inductive switching performance.