Novel etch technologies utilizing atomic layer process for advanced patterning

We demonstrated a high selective and anisotropic plasma etch of Si3N4 and SiC. The demonstrated process consists of a sequence of ion modification and chemical dry removal steps. The Si3N4 etch with H ion modification showed a high selectivity to SiO2 and SiC films. In addition, we have developed selective etch of SiC with N ion modification. On the other hand, in the patterning etch processes, the fabrication of multi-layer films requires the precision of atomic scale XY CD controllability in complex hole patterns. In order to solve the requirement, we have developed Advanced Quasi- Atomic Layer Etching (ALE) technology which achieved X-Y CD control in oval patterns, along with a wider X-Y CD control margin. Furthermore, in the memory fabrication process, it is required to vertically etch the organic film mask pattern in high aspect ratio (A/R) feature. Therefore, we have developed a new approach that combines atomic layer deposition (ALD) technique and organic film etch process. With this method, we are able to achieve the vertical mask profile. Thus, we will show that these new process technologies have a significant potential to solve critical challenges in the various processes in advanced nodes.