Numerical analysis of a new vertical IGBT structure with reduced JFET effect

Abstract The effect of the cell pitch on the forward voltage drops of vertical double-diffused IGBTs has been investigated. Experimental results show that the forward voltage drops in the vertical 800 V rating IGBT with cell pitch of 27, 33 and 39 μm are 3.9, 2.0 and 2.0 V, respectively, at the current density of 100 A cm −2 . Numerical simulations show that the voltage drop due to the inherent JFET region is critical to the cell pitch. A new IGBT structure is proposed based on the experimental and numerical analysis. The proposed IGBT structure reduces the JFET effect without the sacrifice of other device characteristics. Numerical simulations show that the proposed IGBT has lower forward voltage drops with the increase of the breakdown voltage and switching speed compared with conventional IGBTs.