Niraj Ranjan

1200 V high-side lateral MOSFET in junction-isolated power IC technology using two field-reduction layers

A lateral n-channel MOSFET structure in junction-isolated power IC technology using a P-type field-reduction region over an N-type field-reduction region for high-side and low-side switching applications is described. The concept of using two field-reduction layers has been verified by two-dimensional device simulations and by fabricating devices with breakdown voltage in excess of 1200 V.<<ETX>>

The Effect of Incomplete Ionization on the Turn-Off Behavior of FS IGBTs

This letter demonstrates for the first time the effect of the incomplete ionization (I.I.) of the transparent p-anode layer on the static and dynamic characteristics of the field-stop insulated gate bipolar transistors (FS IGBTs). This effect needs to be considered in FS IGBTs TCAD modeling to match accurately the device characteristics across a wide range of temperatures. The acceptor ionization energy (EA) governing the I.I. mechanism for the p-anode is extracted via matching the experimental turn-off waveforms and the static performance with Medici simulator.

Field-stop layer optimization for 1200V FS IGBT operating at 200˚C

This paper is concerned with design considerations for enabling the operation of Field-Stop Insulated Gate Bipolar Transistors (FS IGBTs) at 200 C. It is found that through a careful optimization of the Field-Stop layer doping profile the device has a low leakage current and delivers a favorable tradeoff between the on-state voltage (Von) and turn-off loss (Eoff). An investigation of the adverse effects of increasing the junction temperature on the temperature-dependent properties of the FS IGBTs is also discussed herein.

Superjunction IGBT vs. FS IGBT for 200°C operation

Adverse effects on the temperature-dependent properties of Insulated Gate Bipolar Transistors (IGBTs) are often observed when the junction temperature exceeds 175°C. It is believed that attempts in enabling the operation of IGBTs at 200°C will inevitably introduce penalties in some electrical properties of the device. Therefore, the trade-off relationship between the key parameters must be carefully considered. In this paper, we present for the first time that the Superjunction (SJ) IGBT can deliver the best performance trade-offs between the conduction and turn-off losses while maintaining low leakage current at 200°C when compared with other IGBTs. Moreover, the output and switching characteristics of SJ IGBTs depend on the SJ pillar geometry and the doping level of the SJ pillars. We discover that the structure with disconnected p-body and p-pillar with moderate pillar doping concentration (Dpn) is the key in achieving excellent turn-off behavior without sacrificing the on-state voltage drop (Von) at 200°C.