Etching of Thin Layers to Atomic Layers: An Overview on Latest Etching Technologies

Abstract—This paper shows a description of the latest etching technologies developed to satisfy the scaling demand that has been leading the semiconductor industry since its existence, which involves the need to overcome the challenges that come with this scaling such as getting finer feature, avoiding any residues or defects and the latest one being etching at critical atomic scale dimension. Etching, along with lithography, has defined how far a device can be scaled while running under acceptable electrical and mechanical conditions. Improvements of known etching processes to get better profiles on different materials are described along with all the latest technologies. In the latter part of this paper we will take our discussion to etching of very thin layers or atomic layers by a modern technique called atomic layer etching (ALE) and it’s implementation on oxides and semiconductors. The basic principle of ALE and some characterization tests of ALE will be explored in much detail. The authors will also discuss the advantages of ALE to make positive steps towards sub-10 nm technological node.