Rapid thermal annealing effects on the structural properties and density of defects in SiO2 and SiNx : H films deposited by electron cyclotron resonance

The effect of rapid thermal annealing processes on the properties of SiO2.0 and SiN1.55 films was studied. The films were deposited at room temperatur e from N-2 and SiH4 gas mixtures, and N-2, O-2, and SiH4 gas mixtures, resp ectively, using the electron cyclotron resonance technique. The films were characterized by Fourier transform infrared spectroscopy (FTIR) and electro n paramagnetic resonance spectroscopy. According to the FTIR characterizati on, the SiO2.0 films show continuous stress relaxation for annealing temper atures between 600 and 1000 degrees C. The properties of the films annealed at 900-1000 degrees C are comparable to those of thermally grown ones. The density of defects shows a minimum value for annealing temperatures around 300-400 degrees C, which is tentatively attributed to the passivation of t he well-known E' center Si dangling bonds due to the formation of Si-H bond s. A very low density of defects (5 x 10(16) cm(-3)) is observed over the w hole annealing temperature range. For the SiN1.55 films, the highest struct ural order is achieved for annealing temperatures of 900 degrees C. For hig her temperatures, there is a significant release of H from N-H bonds withou t any subsequent Si-N bond healing, which results in degradation of the str uctural properties of the film. A minimum in the density of defects is obse rved for annealing temperatures of 600 degrees C. The behavior of the densi ty of defects is governed by the presence of non-bonded H and Si-H bonds be low the IR detection limit. (C) 2000 American Institute of Physics. [S0021- 8979(00)05903-X].