1.2 kV Stepped Oxide Trench Insulated Gate Bipolar Transistor with Low Loss for Fast Switching Application

Abstract

A gate engineering technique was used in an insulated gate bipolar transistor (IGBT) for fast switching applications. The modification consists of stepped oxide pattern at gate terminal with n-poly layer sandwiched between two p-poly layers. The oxide thickness increases from top to bottom to create a stepped structure. The oxide is thinner on the channel side and thicker on the collector side. The thinner oxide on the channel side increases gate to emitter charges (QGE) by extracting extra charges along the channel. The presence of these extra charges also increases the collector current density resulting in a reduction in the area specific on-resistance (Ron.A). Furthermore, to elongate the impact of QGC reduction, the low doped p-col region has been facilitated which also play an important role to increase the breakdown voltage by reducing corner electric field. This p-col region creates a charge extraction path to sweep out charges from the drift region during a turn-off event, leading to rapid turn-off. The collective improvement in QGE and QGC provides fast switching to the proposed device by improving turn-off time by 63% and reduces turn-off loss (Eoff) by 55% as compared to the conventional device

Dual‐Stepped Gate Vertical Double‐Diffused Metal‐Oxide‐Semiconductor Field‐Effect Transistor with Enhanced Device Performance

“…In order to increase the device switching and gate control over the channel, space is added between the two gates. [ 14–16 ] 2D device simulation is done and the DSGT and m‐DSGT device is compared with the conventional VDMOS. The outcomes are investigated and enhanced linearity, decreased switching delay, reduction in specific on‐resistance (…”