Plasma-Based Atom-Selective Etching: Advancing Atomic-Scale Smooth Surface Manufacturing for Semiconductor Materials

The development of human manufacturing technologies has entered the phase of atomic and close-to-atomic scale manufacturing (ACSM). The fabrication of semiconductor materials with atomic-scale smooth and damage-free surfaces is one of the core elements of ACSM and is pivotal to the rapid advancement of high-technology fields, such as integrated circuits and quantum computing. However, the simultaneous achievement of both high quality and high efficiency has consistently posed a substantial challenge for contemporary atomic-scale polishing processes. As a chemical-etching-based method, the novel plasma-based atom-selective etching (PASE) technique provides a possible solution to this challenge. A thorough understanding of PASE facilitates ongoing process improvements and the progressive broadening of its applications. In this review, we examine in detail the components of the PASE setup, the excitation principles and physicochemical characteristics of plasma, the atomic-scale material removal mechanisms of PASE, and the polishing outcomes on various semiconductor materials, including single-crystal silica, 4H silicon carbide, gallium nitride, gallium oxide, and diamond. Additionally, we discuss the current technical challenges associated with PASE processes and propose potential solutions. This review provides valuable information and discussions related to PASE, which have significant implications for advancing the development of plasma-ACSM technology.