The heat dissipation path of self-heating effects for the SOI MOSFET by considering the BOX layer and the TiN barrier layer

Abstract

Silicon-on-insulator (SOI) devices are widely utilized in high-performance and high-reliability fields, facing challenges from self-heating effects (SHE). However, the research on heat dissipation path closely related to SHE remains incomplete. This paper initiates an in-depth analysis of thermal effects involving the fine structures within heat dissipation path, using ultrafast pulse I-V measurements combined with thermal simulations. It is found in practical processes that the SHE of scaled-down devices decreased by 40% rather than increase. Research shows the improvement is attributed to the reduction in thickness of buried oxide (BOX) layer between different generations of processes, and the decrease in thermal sensitivity. Based on the two-stage SHE mechanism, the study clarified for the first time that the box layer mainly affects first-stage heat dissipation, and the main timescale of impact is about the first 100ns. In addition, the heat dissipation capability of contact can effectively affect the temperature rise of first-stage SHE. For the first time, we reveal that the TiN barrier layer with low thermal conductivity is the key factor limiting heat dissipation through contact. This study represents the crucial step towards a comprehensive investigation of SHE, offering substantial support for device modeling.