Ion-radical synergy in HfO{sub 2} etching studied with a XeF{sub 2}/Ar{sup +} beam setup
- Department of Applied Physics, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven (Netherlands)
To gain more insight into fundamental aspects of the etching behavior of Hf-based high-k materials in plasma etch reactors, HfO{sub 2} films were etched in a multiple-beam setup consisting of a low energy Ar{sup +} ion beam and a XeF{sub 2} radical beam. The etch rate and etch products were monitored by real-time ellipsometry and mass spectrometry, respectively. Although etching of HfO{sub 2} in XeF{sub 2}/Ar{sup +} chemistry is mainly a physical effect, an unambiguous proof of the ion-radical synergistic effect for the etching of HfO{sub 2} is presented. The etch yield for 400 eV Ar{sup +} ions at a substrate temperature of 300 deg. C was 0.3 atoms/ion for Ar{sup +} sputtering and increased to 2 atoms/ion when XeF{sub 2} was also supplied. The etch yield proved to follow the common square root of ion energy dependence both for pure sputtering and radical enhanced etching, with a threshold energy at room temperature of 69{+-}17 eV for Ar{sup +} ions and 54{+-}14 eV for Ar{sup +} ions with XeF{sub 2}.
- OSTI ID:
- 21137150
- Journal Information:
- Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 8 Vol. 103; ISSN JAPIAU; ISSN 0021-8979
- Country of Publication:
- United States
- Language:
- English
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