Iridium Oxide Schottky Contacts for High Temperature Aluminum Nitride-Based Devices

Researchers at Stanford University have developed Schottky contacts for aluminum nitride-based microelectronic devices. The contacts enable reliable device operation at up to 600 ºC, opening up opportunities for high temperature microelectronic performance.

Microelectronics capable of operating reliably at high temperature are necessary to provide sensing, readout, and telecommunications for applications in the space, aerospace, defense, automotive, and oil and gas sectors. Typical microelectronics produced for commercial, industrial, and military grade electronics, can often only perform reliably at temperatures up to 125 ºC. Above these temperatures, semiconductors fail to meet critical parameters and degradation can cause permanent failure. Aluminum nitride (AlN)-based high electron mobility transistors (HEMTs) that leverage the two-dimensional electron gas (2DEG) have shown promise for high temperature operations. However, the reliability is often limited by the degradation of accompanying metallization and passivation layers.

This technology provides a Schottky gate material as a passivation layer on AlN that can enable reliable high-temperature operation of AlN-based HEMTs. By oxidizing iridium on the AlN surface, devices fabricated with the material have demonstrated increased stability at high temperatures. Specifically, well-known degradation mechanisms in AlN-based devices, such as metal diffusion or electromigration during electrical characterization, are absent even at temperatures up to 600 ºC. Thus, the material offers promise in application to a variety of AlN-based devices where high temperature performance is essential.

Stage of Development: Proof of Concept