Super-thin semiconductor overcomes trade-off between speed and thermal stability

A team led by academician Huang Ru and Professor Wu Yanqing from the School of Integrated Circuits at Peking University has developed a super-thin, high-performance semiconductor with enhanced heat conductivity, enabled by a silicon carbide (SiC) substrate. The research, published in Nature Electronics under the title “Amorphous indium tin oxide transistors for power amplification above 10 GHz,” marks a significant step forward in next-generation radio-frequency (RF) electronics.

Amorphous oxide semiconductors (AOS) enable low-temperature, large-area, and chip-compatible processing with high carrier mobility. However, their inherently low thermal conductivity leads to self-heating effects, which limit top-gate scaling and high-frequency operation in applications such as 5G communications and the Internet of Things. Overcoming this trade-off between speed and thermal stability remains a central challenge.

This breakthrough using a SiC substrate overcomes the trade-off between speed and thermal stability in AOS, paving the way for low-cost, flexible, and chip-compatible RF electronics. It demonstrates how combining high-frequency design with effective thermal management can deliver both performance and reliability in high-speed devices.

The PKU team designed a 120 nm short-channel top-gate indium tin oxide (ITO) transistor on a high-thermal-conductivity SiC substrate, effectively eliminating self-heating even under a high supply voltage of 3 V and high temperature of 125°C. Furthermore, multiple tests have revealed that this transistor has broken AOS device records in speed, heat dissipation, and power.

The results show that a highly thermally conductive SiC substrate can effectively improve thermal management for ultrathin-body ITO channels in both direct current (DC) and RF performance. This provides a key advantage over other bulk channel materials that typically have thicknesses in the range of a few micrometers.

These devices could find potential use in high-speed applications, including RF power amplifiers and data communications. Moreover, AOS could serve as thin-channel materials for future back-end-of-line-compatible electronics, offering a pathway toward scalable and energy-efficient RF integration.