| AVS 66th International Symposium & Exhibition | |
| Electronic Materials and Photonics Division | Thursday Sessions |
| Session EM+AP+MS+NS+TF-ThM |
| Session: | Advanced Processes for Interconnects and Devices |
| Presenter: | Gerhard Franz, Munich University of Applied Sciences, Germany |
| Authors: | G. Franz, Munich University of Applied Sciences, Germany V. Sushkov, Munich University of Applied Sciences, Germany W. Oberhausen, Technische Universität München, Germany R. Meyer, Technische Universität München, Germany |
| Correspondent: | Click to Email |
During our research to define a contact which can be serve as thin hard mask in III/V semiconductor processing, we focused on the Bell contact which consists of Ti/Pt(Mo)/Au and chlorine-based plasmas generated by electron cyclotron resonance. For platinum, we identified PF3 as main component which acts comparable to CO [1]. This fact triggered our search for suited etchants for gold and copper. For Au, the best ambient is a mixture of CH4, Cl2, and O2 which is stabilized by Ar [2]. This mixture generates residual-free etching of metal films which are clearly free of "fencing" and "hear's ears."
The etching process has been established up to thicknesses of half a micron which is the typical thickness of metal films on the p-side of laser devices. With the aid of optical emission spectroscopy, the generation of CO could be proven [3]. This reagent seems to be the main component for real etching without residual fencing.
[1] G. Franz, R. Kachel, and St. Sotier, Mat. Sci. Semicond. Proc. 5, 45 (2002)
[2] G. Franz, R. Meyer, and M.-C. Amann, Plasma Sci. Technol. 19, 125503 (2017)
[3] G. Franz, W. Oberhausen, R. Meyer, and M.-C. Amann, AIP Advances 8, 075026 (2018)