Carbon Tetrafluoride (CF4)
Carbon Tetrafluoride is a source of fluorine or carbon fluoride free radicals used in a variety of wafer etch processes. Carbon Tetrafluoride is used with oxygen to etch polysilicon, silicon dioxide, and silicon nitride. Carbon Tetrafluoride is relatively inert under normal conditions and is an asphyxiant. Under RF plasma conditions, the fluorine radicals are typically in the form of CF3 or CF2. A higher purity Carbon Tetrafluoride results in superior control of the process, which results in better dimensional and profile control. Other halocarbons, as well as the presence of air or oxygen, are detrimental to the control of the anisotropic etch.
Physical Constants |
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Maximum Impurities for ULSI Plus Grade: 99.997% |
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Maximum Impurities for Giga Class Grade: 99.999% |
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