The RF-ready GaN-on-silicon with lower parasitic losses

A new technology addresses a key performance barrier limiting the use of GaN-on-silicon semiconductors in mainstream RF applications. According to Scott Bibaud, president and CEO of Atomera, this will change the economics of GaN in RF by unlocking breakthrough RF performance on low-cost silicon substrates.

Gallium nitride (GaN) devices for high-performance RF applications are typically built on silicon carbide (SiC) substrates; while they offer robust performance, they are also costly and difficult to scale. On the other hand, silicon substrates offer a lower-cost, more scalable foundation with the potential to support larger wafer sizes and greater compatibility with standard silicon manufacturing.

However, GaN-on-silicon underperforms in RF applications due to parasitic channel losses that reduce efficiency, especially at high frequencies. Enter Atomera’s Mears Silicon Technology (MST), which claims to reduce these losses while offering robust linearity and lower-cost GaN solutions for 5G and other high-frequency RF devices.

MST—a quantum-engineered thin-film technology—introduces a thin, oxygen-modified layer near the surface of the silicon wafer to create a more favorable platform for GaN growth, making silicon a more viable foundation for high-performance RF devices. This controlled layer modifies the silicon lattice structure and helps block the diffusion of electrical dopants. That, in turn, improves crystal quality at the GaN-silicon interface.

MST can improve various wafer-level reliability measures in nitrided oxide planar devices. Source: Atomera

Incize, which provides characterization and modeling services for RF semiconductors, has performed RF characterization of the first MST-enabled samples. The Belgian company reports a substantial reduction in parasitic interface charge and a significant reduction in RF losses.

“Beyond the small-signal improvements, the large-signal results are particularly compelling,” said Mostafa Emam, founder and CEO of Incize. “Then there is a linearity benefit that extends into the high-power regime, approaching performance levels typically associated with advanced RF SOI technologies.”

In Atomera’s own testing, MST enabled more than a 10x reduction in parasitic channel charge, reducing a key mechanism of RF power loss and supporting improved high-frequency GaN device performance. The test data also shows that MST enables devices to handle significant power while maintaining signal quality—linearity—under stress.

Robert Mears, founder and CTO of Atomera, is quick to add that linearity is a top concern for RF designers. “The new data shows MST GaN-on-silicon achieving both the ultra-low RF losses and linearity metrics of advanced trap-rich RF SOI,” he said. “At the benchmark input power of 30 mW, the linearity is exceptional, 1000x better than the GaN-on-silicon reference wafer.”

Atomera, a semiconductor materials and technology licensing company, is based in Los Gatos, California.

Related Content

• GaN on silicon or SiC?
• A Guide to GaN-on-Silicon
• A brief history of gallium nitride (GaN) semiconductors
• Why RF Technologies Should Consider GaN Over Silicon
• GaN-on-Si Technology Makes Headway in RF Applications

The post The RF-ready GaN-on-silicon with lower parasitic losses appeared first on EDN.