Development of a low-damage atomic layer etching system for SiC with high precision and enhanced surface quality

• This work reports the first application of the BCl 3 -Ar ALE system to SiC. • This paper comprehensively elucidates the mechanism of BCl 3 -Ar ALE system. • Optimal ALE parameters determined experimentally for desirable etching results. • This paper is grounded in traditional ALE, the BCl 3 -Ar ALE process notably reduces damage caused by ICP etching, thereby enhancing surface quality. As a prominent third-generation semiconductor material, SiC (silicon carbide) has found widespread use in advanced high-power and high-frequency devices. To enhance the performance of SiC-based devices, developing a low-damage etching technique is essential. This work comprehensively developed a novel 4H-SiC ALE (atomic layer etching) system utilizing a BCl 3 -Ar loop. We systematically investigated its self-limiting mechanism and evaluated the resulting surface roughness. In the modification step, we examined the relationship between the thickness of the modified layer and parameters such as ICP power, and also analyzed the modification mechanism. In the etching step, we explored the effects of parameters like bias power and ICP power on the etching results, identified the self-limiting windows, and analyzed the etching mechanism. Our ALE system achieves an etch rate of 4.8 Å/cycle, which is considered one of the highest in existing SiC ALE processes. Additionally, damage repair through the system significantly reduced the surface roughness of SiC to around 1 Å after just three loops, offering precise control over surface quality. This breakthrough in SiC etching technology enhances the capabilities of precision processing and opens up new possibilities for SiC applications in microelectronics and optoelectronics.