White Paper

Enabling reliable normally-off recessed gate MISHEMT fabrication for power electronics applications

Author

Aileen O'Mahony
Atomic Scale Processing Product Manager, Oxford Instruments Plasma Technology

Our communication-centric and data-driven world has created a massive demand for efficient, reliable, and cost-effective power supplies and amplifiers. Wide bandgap materials like gallium nitride (GaN) have significant benefits over traditional siliconbased power electronics. In terms of transistor properties, GaN offers higher breakdown voltage, faster switching speed, and lower onresistance, delivering high voltage, high frequency device performance with improved efficiency and smaller device geometries. GaN devices also generate less heat, and can operate at higher temperatures, making them ideal to achieve high-performance in harsh environments.

Atomic layer etch (ALE) is cyclical etch process that allows for very fine control of the etched thickness, typically with an etch rate on the order of Å/cycle. This allows for excellent depth control which is beneficial to applications such as a recessed gate MISHEMT where control of both the remaining AlGaN thickness and limiting the GaN/AlGaN surface damage during processing are equally important.

The combined solution of ALE and Etchpoint provide key processing and performance benefits that enable fabrication of device geometries previously deemed too challenging.