Wet etch, dry etch, and MacEtch of beta-Ga2O3: A review of characteristics and mechanism

beta-Ga2O3, a promising ultra-wide bandgap material for future high-power electronics and deep-ultraviolet optoelectronics applications, has drawn tremendous attention in recent years due to its wide bandgap of similar to 4.8 eV, high breakdown electric field, and availability of substrates. However, the reported etch behavior of beta-Ga2O3 and the quality of etched surfaces, as well as the associated interface characteristics, could limit the performance of beta-Ga2O3 devices. In this article, the etchings of beta-Ga2O3, including regular wet etching, photoelectrochemical etching (PEC), reactive ion etching (RIE) and metal-assisted chemical etching (MacEtch), are reviewed. A comparison of the etch rate, orientation dependence, aspect ratio, etching mechanism, and surface quality for each of these etching methods is presented and the step-by-step reactions in PEC and MacEtch are proposed to elucidate the etch mechanism. The challenges for these etching techniques for beta-Ga2O3 are discussed.

Automated summary

This article reviews the etching of beta-Ga2O3 using various methods, comparing their performance and discussing the challenges faced by these etching techniques for beta-Ga2O3.