Integration of buried insulators with high thermal conductivity in SOI MOSFETs: Thermal properties and short channel effects

Abstract

SOI circuits exhibit excellent performance and scalability but suffer from self-heating. Systematical 2D simulations demonstrate that the thermal dissipation in SOI MOSFETs can be improved dramatically by replacing the buried oxide with high thermal conductance insulators. The self-heating can be reduced by as much as 50–100 °C. Yet, these materials feature high- K dielectric constant, which also affects the electrical properties: more severe short-channel effects, parasitic capacitances and drain-to-body fringing fields. The conciliation between the thermal and electrical properties of advanced SOI MOSFETs (50 nm long, 10 nm thick) is examined by comparing different SOI materials (air, SiO 2, diamond, AlN, Al 2O 3, SiC) and MOS architectures. We demonstrate the advantage of a ground plane (GP) located under the buried insulator (BOX). Diamond is excellent candidate for relatively thick BOX whereas Al 2O 3 and SiC are suitable for ultra-thin BOX. These novel structures can be fabricated by wafer bonding technology.