Remote plasma source for hydrogen, NF3, CF4, SF6 plasma
SEMI-KLEEN sapphire remote plasma cleaner is designed to support aggressive and corrosive process gases for in-situ plasma cleaning in semiconductor equipment, such as EUV/DUV system, film deposition and coating equipment. The plasma chamber has been replaced with the more chemically resistant sapphire tube. Vacuum seal design and chamber material selection have been optimized to support corrosive radicals inside the plasma. For applications that plasma etching of quartz chamber is a concern, SEMI-KLEEN sapphire is a better choice over traditional quartz chamber plasma source.
SEMI-KLEEN Sapphire remote plasma source and 150Watt 3U half-rack controller
Even though quartz (SiO2) is considered as very stable, hydrogen plasma can slowly etch quartz and create volatile hydroxysilane/silanol fragments —species of the form HₓSi(OH)₄₋ₓ (and related radicals). For sensitive semiconductor applications, or for EUV optics chamber cleaning applications, volatile hydroxysilane/silanol can become a concern of contaminaiton. Sapphire (Al₂O₃) is much more resistant to hydrogen plasma because there is no volatile Al–H chemistry in this regime. For semiconductor applicaitons (including semiconductor cleaning and EUV lithography related applications) , sapphire is more preferrable choice of mateirals than quartz to generate hydrogen plasma.
It’s well-know that fluorine based plasma can etch SiO2 by forming volatile silicon tetrafluoride. For aluminum based materials, AlF₃(s) and AlOₓFᵧ(s) has very low vapor pressure. Therefore, NF3, CF4, SF6 plasma source should be constructed with aluminum oxide (Sapphire or alumina). Sapphire is the crystalized aluminum oxide with more chemcial resistant than alumina.
SEMI-KLEEN sapphire remote plasma source has been used to clean EUV equipment optics and chamber, to clean samples surface prior to thin film deposition, and to remove carbon and oxygen contaminations from a metal, semiconductor, and compound semiconductor surface. Customer results show that SEMI-KLEEN plasma source can remove carbon and oxygen contaminants from InGaAs sample with just 2-second hydrogen plasma. SEMI-KLEEN Sapphire plasma source can be used on a downstream chamber pumped by a turbo pump or roughping pump only. It can be operated in the pressure range from <0.5mTorr to over 2Torr.
