A physically based thermal model for high‐voltage thin‐film SOI LDMOS in short circuit operation

Abstract

AbstractThe heat generation process inside thin‐film silicon‐on‐insulator LDMOS structures accounting for Linear Doping Profile (LDP) or Variation on Lateral Doping (VLD) is analysed in this paper by means of numerical simulation tools and analytical modeling. A uniform heat density, mainly due to the Joule effect, has been demonstrated to be generated in a rectangular shaped heat source, contained in the drift region. The dimensions of such a heat source are dependent on the drain bias as well as on the geometrical/technological structure parameters. Accordingly, we have developed an analytical electro‐thermal model to provide physical insight into the heat generation process, and to predict dynamic temperature distribution by means of heat flow equation approach. The model is suitable for typical short circuit operation when the internal device temperature raises critically. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)