Regensburg 2002 – wissenschaftliches Programm
HL 38.57: Poster
Donnerstag, 14. März 2002, 16:30–19:00, Poster A
Bonding Mechanisms of Silicon Wafers Revealed by Multiple Internal Transmission Infrared Measurements — •Cameliu Himcinschi1, Matthias Bartzsch1, Marion Friedrich1, Karla Hiller2, Thomas Gessner2, and Dietrich R.T. Zahn1 — 1Institut für Physik, Technische Universität Chemnitz, D-09107 Chemnitz, Deutschland — 2Zentrum für Mikrotechnologien, Technische Universität Chemnitz, D-09107 Chemnitz, Deutschland
Multiple Internal Transmission (MIT) technique was used for infrared (IR) spectroscopic investigations of buried interfaces in silicon bonded wafers. Si wafers with different chemical pre-treatments (RCA, oxygen plasma activation) were bonded at room temperature and further annealed up to 400oC. The evolution of the chemical species at the bonded interface was monitored during annealing using MIT IR spectroscopy. The IR spectra show that a rearrangement of the atoms at the buried interface takes place. With increasing annealing temperature the adsorbed water (broad band centred at 3400 cm−1) is partially diffusing away from the bonded interface and the Si-OH (silanol) groups are transformed from No-dqassociatedNo-dq (OH bonded: bands at 3600-3700 cm−1) to No-dqisolatedNo-dq ones (sharp band at 3737 cm−1). Additionally a portion of the silanol groups is converted into siloxane. The mechanisms of bonding depend on temperature and duration of annealing and also on chemical pre-treatments of the Si surfaces.