Research progress of high precision and selective atomic layer etching technology

With the rapid development of semiconductor technology, the key sizes of chips continue to shrink, and even require complex three-dimensional structures, such as FinFET and 3D NAND flash memory. The development of these technologies has placed extremely high demands on the etching process, especially in terms of low damage, selectivity and precision. As a high-precision atomic-scale micromachining technology, atomic layer etching (ALE) has gradually become one of the key technologies in semiconductor manufacturing. In this paper, the advantages of ALE compared to existing etching technology, basic principles and classification of ALE will be introduced. Moreover, special interest will be placed on the review and discussion of ALE technology of different materials, the application of selective ALE in advanced semiconductor devices and the application of ALE in the field of selective deposition.