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Modification of Si(100)‐Surfaces by SF 6 Plasma Etching — Application to Wafer Direct Bonding
Author(s) -
Reiche M.,
Gösele U.,
Wiegand M.
Publication year - 2000
Publication title -
crystal research and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.377
H-Index - 64
eISSN - 1521-4079
pISSN - 0232-1300
DOI - 10.1002/1521-4079(200007)35:6/7<807::aid-crat807>3.0.co;2-j
Subject(s) - reactive ion etching , wafer , etching (microfabrication) , wafer bonding , ellipsometry , amorphous solid , plasma etching , layer (electronics) , materials science , scanning electron microscope , silicon , analytical chemistry (journal) , plasma , direct bonding , ion , chemistry , chemical engineering , nanotechnology , crystallography , thin film , composite material , optoelectronics , chromatography , organic chemistry , physics , quantum mechanics , engineering
The effect of plasma pretreatments (reactive ion etching in SF 6 and SF 6 /O 2 ) on Si/Si wafer direct bonding was investigated. Etching in SF6 caused a bonding behaviour generally known from hydrophobic (HF etched) samples, whereas adding O 2 to the feed gas caused the Si(100) surfaces to become hydrophilic and spontaneous bonding was achieved. The structure of the bonded interfaces were analysed by high‐resolution electron microscopy, ellipsometry, multiple internal reflection spectroscopy, and secondary ion mass spectroscopy. All the plasma treatments result in an interface structure analogous to that known from bonded hydrophobic wafer pairs. The interface does not involve an additional layer such as an SiO 2 or an amorphous Si layer but small one‐dimensional defects forming a disturbed layer about 1 to 2 nm thick.