AVS 51st International Symposium
    Plasma Science and Technology Monday Sessions
       Session PS1-MoA

Paper PS1-MoA8
Real-time Spectroscopic Studies of Si Etch Dynamics

Monday, November 15, 2004, 4:20 pm, Room 213A

Session: Plasma Surface Interactions in Etching
Presenter: A.A.E. Stevens, Eindhoven University of Technology, The Netherlands
Authors: A.A.E. Stevens, Eindhoven University of Technology, The Netherlands
J.J.H. Gielis, Eindhoven University of Technology, The Netherlands
M.C.M. van de Sanden, Eindhoven University of Technology, The Netherlands
H.C.W. Beijerinck, Eindhoven University of Technology, The Netherlands
W.M.M. Kessels, Eindhoven University of Technology, The Netherlands
Correspondent: Click to Email
Nanometer scale control during IC, MEMS/NEMS and photonic device production becomes more and more an issue. Plasma etching and ion beam processing cause the creation of surface roughness and defects, such as dangling and strained bonds. The roughness and defects resulting from the production process end up at critical interfaces in the devices and, thus, influence their performance in a negative way. Therefore, fundamental studies of the creation of roughness and dangling/strained bonds in plasma and ion beam processing of silicon are required. In the past, mass spectrometry studies in well-characterized beam-etching experiments revealed a great deal of information regarding the synergy between ions and etchant during Si etching. At present, more detailed information is desired and can be obtained with spectroscopic surface diagnostics, which have made significant advances over the last years. Hence, spectroscopic ellipsometry (SE) and second harmonic generation (SHG) are employed in situ and real-time during the etching of Si with beams of Ar@super +@ [10-2000 eV] and XeF@sub 2@. By means of SE the surface roughness is measured. If the etching is dominated by XeF@sub 2@ etching, the surface becomes rough (d@rough@ ~ 1-10 nm). However, when Ar@super +@ ions are driving the etch process, the surface remains relatively smooth (d@rough@ < ~1 nm). Complemented with atomic force microscopy measurements, the dynamic roughness scaling theory, expressed in parameters @alpha@ and @beta@, is applied to find the origin of the roughening processes during the etching. In order to study the creation of dangling and strained bonds SHG studies are being carried out. The role of the ions and etchant in the creation of roughness and defects at etched Si surfaces will be discussed on the basis of the results obtained with these surface-sensitive spectroscopic analysis techniques.