AVS 56th International Symposium & Exhibition
    Plasma Science and Technology Thursday Sessions
       Session PS2-ThM

Paper PS2-ThM11
Vacuum Ultraviolet Plasma Emission in a Capacitively-Coupled Dielectric Etch Reactor

Thursday, November 12, 2009, 11:20 am, Room B2

Session: Plasma Sources
Presenter: E.A. Hudson, Lam Research Corp.
Authors: E.A. Hudson, Lam Research Corp.
M. Moravej, Lam Research Corp.
M. Block, Lam Research Corp.
S. Sirard, Lam Research Corp.
D. Wei, Lam Research Corp.
K. Takeshita, Lam Research Corp.
B. Jinnai, Tohoku University, Japan
S. Samukawa, Tohoku University, Japan
Correspondent: Click to Email
Plasma optical emission in the visible and ultraviolet (UV) ranges is widely used to characterize the properties of thin-film processing plasmas. Emission in the vacuum ultraviolet (VUV) range is less commonly detected due to the challenges of eliminating air from the optical path. However the interaction of VUV radiation with the substrate may be important in plasma processing, particularly for device damage and for the modification of sensitive materials such as low-k dielectrics and 193nm photoresist. To improve the understanding of these mechanisms, a windowless optical system was incorporated onto a commercial capacitively-coupled confined-plasma dielectric etch reactor. VUV and UV emission spectra in the 40 – 230nm range were measured for a range of plasma conditions, including simple single-gas plasmas and more complex etching plasmas. The spectra showed a strong dependence on gas chemistry, due to the characteristic emission lines associated with the plasma atomic and molecular composition. More importantly, the frequency of plasma electrical excitation was found to influence the VUV spectra. Correlations were observed between plasma emission in specific wavelength ranges and process-induced low-k dielectric damage.