| AVS 66th International Symposium & Exhibition | |
| Atomic Scale Processing Focus Topic | Thursday Sessions |
| Session AP+PS+TF-ThM |
| Session: | Thermal Atomic Layer Etching |
| Presenter: | Andreas Fischer, Lam Research Corporation |
| Authors: | A. Fischer, Lam Research Corporation A. Routzahn, Lam Research Corporation T.B. Lill, Lam Research Corporation |
| Correspondent: | Click to Email |
In this work, we have characterized the reaction of aluminum oxide via the DMAC ligand exchange mechanism.
Fluorination studies of aluminum oxide were performed using NF3, CF4 or anhydrous HF, respectively. We also explored various methods of fluorination of the oxide surface such as thermal, in-situ or remote plasma, respectively, and found that a sufficient fluorine concentration could be obtained with either of the methods or reactants to enable atomic layer etching (ALE).
To understand reaction kinetics, we examined the interaction of aluminum fluoride (AlF3) films with DMAC. We found that AlF3 etched until it was completely consumed by DMAC. An analysis of its temperature-dependence allowed us to extract activation energies for the ligand exchange mechanism.
In a third part we demonstrated the utility of HF/DMAC reaction for isotropic ALE applied to nanometer-size metal oxide structures on wafers. Various metal oxides were etched and selectivities between oxides and potential mask materials were determined.