Microstructural modifications induced by rapid thermal annealing in plasma deposited SiOxNyHz films

© 2003 American Institute of Physics. The authors acknowledge Centro de Asistencia a la Investigacıón (CAI) de Implantación Iónica [Universidad Complutense de Madrid (UCM)] for use of the deposition system and RTA furnace. CAI de Espectroscopia (UCM). Is acknowledged for providing the FTIR spectrometer. This work was partially financed by the CICYT (Spain) under Contract No. TIC 01-1253.
The effect of rapid thermal annealing (RTA) processes on the structural properties of SiOxNyHz films was investigated. The samples were deposited by the electron cyclotron resonance plasma method, using SiH4, O-2 and N-2 as precursor gases. For SiOxNyHz films with composition close to that of SiO2, which have a very low H content, RTA induces thermal relaxation of the lattice and improvement of the structural order. For films of intermediate composition and of compositions close to SiNyHz, the main effect of RTA is the release of H at high temperatures (T>700degreesC). This H release is more significant in films containing both Si-H and N-H bonds, due to cooperative reactions between both kinds of bonds. In these films the degradation of structural order associated to H release prevails over thermal relaxation, while in those films with only N-H bonds, thermal relaxation predominates. For annealing temperatures in the 500-700degreesC range, the passivation of dangling bonds by the nonbonded H in the films and the transition from the paramagnetic state to the diamagnetic state of the K center result in a decrease of the density of paramagnetic defects. The H release observed at high annealing temperatures is accompanied by an increase of density of paramagnetic defects.
CICYT (Spain)
Depto. de Estructura de la Materia, Física Térmica y Electrónica
Fac. de Ciencias Físicas
TRUE
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