Exploring the self-limiting atomic layer etching of AlGaN: A study of O2-BCl3 and chlorinate-argon systems

Abstract

GaN/AlGaN, known as the third-generation semiconductor, is widely used in advanced power and RF devices. A precise and low-damage etch process is essential for the preparation of recessed-gate enhancement-mode GaN high electron mobility transistors. Atomic layer etching (ALE) offers novel opportunities during the ultraprecision manufacturing process by splitting etch process into a surface modification step and a modified layer removal step. In this work, two self-limiting AlGaN ALE systems (O2-BCl3 and chlorinate-argon) are reported in detail. The results of the two systems are analyzed and compared. This research provides a deep insight into the ALE mechanism of AlGaN and a broad cognition for applying ALE to engineering problems.