AVS 54th International Symposium | |
Plasma Science and Technology | Tuesday Sessions |
Session PS1-TuA |
Session: | Plasma Etching for Advanced Interconnects II |
Presenter: | L.H. Chen, Tokyo Electron AT LTD, Japan |
Authors: | L.H. Chen, Tokyo Electron AT LTD, Japan S. Tahara, Tokyo Electron AT LTD, Japan R. Asako, Tokyo Electron LTD, Japan K. Yamazaki, Tokyo Electron AT LTD, Japan Y. Ohsawa, Tokyo Electron LTD, Japan Y. Chiba, Tokyo Electron AT LTD, Japan H. Nagai, Tokyo Electron LTD, Japan K. Kubota, Tokyo Electron AT LTD, Japan K. Maekawa, Tokyo Electron LTD, Japan |
Correspondent: | Click to Email |
Extreme Ultra low-k (eULK) dielectrics with k-value of below 2.2 have been extensively evaluated for 32 nm technology and beyond. The eULK dielectrics exert new challenges in etch/ash plasma process and post treatment process. In photo resist stripping, hydrogen radical is known as a reactant to minimize low-k damage compared to oxygen. Hydrogen radical, however, does not restore etch-induced low-k damage. Thus, a low-k restoration following to hydrogen radical stripping should be processed subsequently. At this point, we picked up the silylation process with vaporized silazanes as a low-k restoration technique so that all processed from etch to low-k restoration could be integrated in a dry system for high restoration effectiveness and productivity. In this study, we investigated the effects of combining H radical treatment and low-k restoration by using spin on dielectric blanket film (k=2.2). It was confirmed that a hydrogen process/treatment did not only minimize low-k damage in photo resist stripping but also reduce oxygen in copper, and decrease fluorine in low-k film by Thermal Desorption Spectroscopy (TDS) analysis. Moreover, the combination of a hydrogen treatment and low-k restoration in a dry system without air exposure showed that k value, leakage current, H2O degas amount by TDS, and carbon profile by Secondary Ion Mass Spectroscopy (SIMS) were improved and recovered to near pristine low-k material.