Effect of different frequency combination on ArF photoresist deformation and silicon dioxide etching in the dual frequency superimposed capacitively coupled plasmas
- School of Advanced Materials Science and Engineering, Suwon, Kyunggi-do 440-746 (Korea, Republic of) and Center for Advanced Plasma Surface Technology, Sungkyunkwan University, Suwon, Kyunggi-do 440-746 (Korea)
This study investigated the deformation of ArF photoresist (PR) and the etch characteristics of ArF PR and SiO{sub 2} layers in a dual frequency superimposed capacitively coupled plasma (DFS-CCP) etcher with multiple frequency sources under different frequency combinations in C{sub 4}F{sub 8}/CH{sub 2}F{sub 2}/O{sub 2}/Ar capacitively coupled plasma. In the DFS-CCP etcher, the high-frequency (f{sub HF}) power (13.56, 27, and 60 MHz) was varied to control the plasma density while a fixed low frequency (f{sub LF}) of 2 MHz was used to control the ion bombardment energy to the wafer. The morphology of the blanket ArF PR surfaces and line patterns of the ArF PR after etching showed a significant increase in the level of surface roughening and deformation with increasing HF source frequency (f{sub HF}) from 13.56 to 60 MHz under the same V{sub dc} and gas flow conditions. This was attributed to the increased F radical flux and possibly ion flux on the surface. The V{sub dc} also played an important role in increasing the surface roughness and ArF PR deformation, which was presumably due to the increased ion flux and ion-bombardment energy, respectively. The etch rates of the ArF PR and silicon oxide layers increased significantly with increasing |V{sub dc}| and f{sub HF} possibly due to the increased ion energy and ion/radical flux density, respectively. The etch selectivity of the SiO{sub 2} layer to the ArF PR was enhanced most significantly by the increase in CH{sub 2}F{sub 2} flow rate due to the formation of a thicker and C-rich CF{sub x} polymer on the oxide and PR surfaces.
- OSTI ID:
- 20777326
- Journal Information:
- Journal of Vacuum Science and Technology. A, International Journal Devoted to Vacuum, Surfaces, and Films, Journal Name: Journal of Vacuum Science and Technology. A, International Journal Devoted to Vacuum, Surfaces, and Films Journal Issue: 4 Vol. 24; ISSN 1553-1813
- Country of Publication:
- United States
- Language:
- English
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