Comparison of Self-Heating effect between SOI and SOS MOSFETs

In this research, we perform an in-depth analysis of the self-heating effect (SHE) and heat transfer characteristics of devices fabricated on silicon-on-insulator (SOI) and silicon-on-silicon carbide (SOS) substrates using technology computer-aided design (TCAD) numerical simulations. The results reveal that, under identical operating conditions, the maximum lattice temperature increase in SOI devices is approximately 3.9 times higher than that in SOS devices, highlighting the superior thermal management properties of SOS devices. When SHE is considered at a gate voltage of 1.8 V, the leakage current in SOS devices decreases by about 27 % compared to SOI devices, demonstrating enhanced resistance to SHE in SOS devices. Analysis of the thermal dissipation pathways reveals that for SOI devices, heat primarily dissipates through the source and drain regions within the device layer, while for SOS devices it predominantly dissipates through the silicon carbide substrate due to its high thermal conductivity, thereby significantly improving thermal dissipation efficiency. Additionally, our research uncovers a correlation between increasing device layer thickness and elevated lattice temperature for both SOI and SOS structures. This phenomenon is closely associated with thermal-electric coupling effects and changes in device thermal resistance.