AVS 46th International Symposium
    Electronic Materials and Processing Division Tuesday Sessions
       Session EM-TuM

Paper EM-TuM7
FTIR Studies of the Nitridation of Si(100)-(2x1) and Oxidized Silicon

Tuesday, October 26, 1999, 10:20 am, Room 608

Session: Si Surface Chemistry and Etching, Passivation, and Oxidation
Presenter: Y.J. Chabal, Bell Laboratories, Lucent Technologies
Authors: K.T. Queeney, Bell Laboratories, Lucent Technologies
Y.J. Chabal, Bell Laboratories, Lucent Technologies
J. Eng, Jr., Bell Laboratories, Lucent Technologies
K. Raghavachari, Bell Laboratories, Lucent Technologies
X. Zhang, Rutgers University
E. Garfunkel, Rutgers University
S.B. Christman, Bell Laboratories, Lucent Technologies
E.E. Chaban, Bell Laboratories, Lucent Technologies
Correspondent: Click to Email
We have investigated the incorporation of N into Si and SiO@sub 2@ with IR absorption spectroscopy, in order to elucidate the mechanisms by which nitridation and oxynitridation influence the structure and thus the electrical characteristics of Si/SiO@sub 2@ interfaces. Studies of the adsorption and decomposition of NH@sub 3@ on Si(100)-(2x1) demonstrate that the chemistry of this nitriding agent is governed by a combination of dissociative and molecular adsorption, with metastable NH@sub 3(a)@ characterized by a dramatically redshifted NH@sub 3@ deformation mode. Higher coverages and temperatures favor NH@sub 3@ dissociation into H and NH@sub 2@, followed by competing desorption and decomposition. The mechanism for N insertion into the Si substrate is studied via repeated cycles of NH@sub 3@ dosing and annealing with post-dosing of atomic H to identify discrete N-containing structures by the perturbation in @nu@(Si-H) frequencies. Oxynitride growth by reaction of NO on Si(100)-(2x1) reveals the interplay between oxygen and nitrogen, as both Si-O (~900 cm@super -1@) and Si-N (~775 cm@super -1@) modes exhibit frequencies distinct from those observed for pure oxide and nitride films. These fundamental growth studies are used to interpret structural details contained in the complex spectra of device-quality nitride and oxynitride films grown on Si.