Quantum cascade laser based monitoring of CF{sub 2} radical concentration as a diagnostic tool of dielectric etching plasma processes
- Leibniz Institute for Plasma Science and Technology (INP Greifswald), Felix-Hausdorff Str. 2, 17489 Greifswald (Germany)
- Fraunhofer Institute for Electronic Nano Systems, Technologie-Campus 3, 09126 Chemnitz (Germany)
- GLOBALFOUNDRIES Dresden Module One LLC and Co. KG, Wilschdorfer Landstr. 101, 01109 Dresden (Germany)
Dielectric etching plasma processes for modern interlevel dielectrics become more and more complex by the introduction of new ultra low-k dielectrics. One challenge is the minimization of sidewall damage, while etching ultra low-k porous SiCOH by fluorocarbon plasmas. The optimization of this process requires a deeper understanding of the concentration of the CF{sub 2} radical, which acts as precursor in the polymerization of the etch sample surfaces. In an industrial dielectric etching plasma reactor, the CF{sub 2} radical was measured in situ using a continuous wave quantum cascade laser (cw-QCL) around 1106.2 cm{sup −1}. We measured Doppler-resolved ro-vibrational absorption lines and determined absolute densities using transitions in the ν{sub 3} fundamental band of CF{sub 2} with the aid of an improved simulation of the line strengths. We found that the CF{sub 2} radical concentration during the etching plasma process directly correlates to the layer structure of the etched wafer. Hence, this correlation can serve as a diagnostic tool of dielectric etching plasma processes. Applying QCL based absorption spectroscopy opens up the way for advanced process monitoring and etching controlling in semiconductor manufacturing.
- OSTI ID:
- 22415113
- Journal Information:
- Applied Physics Letters, Vol. 106, Issue 3; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
SUPERCONDUCTIVITY AND SUPERFLUIDITY
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
CARBENES
CARBON COMPOUNDS
CONCENTRATION RATIO
DIELECTRIC MATERIALS
ETCHING
FLUORINE COMPOUNDS
HYDROGEN COMPOUNDS
MINIMIZATION
OXYGEN COMPOUNDS
PLASMA
SEMICONDUCTOR LASERS
SEMICONDUCTOR MATERIALS
SILICON COMPOUNDS