Masaaki Sakuta

Properties of PECVD SiO x N y Films as Selective Diffusion Barrier

Properties of silicon oxynitride films on substrates formed by plasma‐enhanced chemical vapor deposition (PECVD) employed as diffusion barriers have been reported. The relation between the refractive index and the composition of films, the thermal stability and the barrier ability to Zn impurity diffusion have been discussed; and we propose an optimum range of the refractive index of the PECVD films for excellent diffusion barriers and a suitable structure for selective diffusion barriers.

Stress‐Induced Spectral Changes in Raman Spectra of n ‐ GaAs Encapsulated with Si3 N 4 Films

Raman spectra and wafer bending of encapsulated with films were observed. The stresses which are estimated from wafer bending by the Timoshenko relation depend on the thickness of encapsulated films. The changes in Raman spectra also depend on the film thickness. There is good correlation between the variation of the ratio of peak heights of longitudinal optical to coupled plasmon‐longitudinal optical modes in the Raman spectra, (LO/L‐), and the variation of stress deduced from wafer bending. The variation of the LO/L‐ modes with film thickness was explained by the change in space charge layer thickness and disordering by inhomogeneous strain.