The diffusion-barrier behavior of films which were formed by ECR plasma nitridation was investigated. It was noted that they exhibited good barrier characteristics when a radio-frequency bias was applied to the substrate during nitridation; even though the film was less than 6nm thick. Applying such a bias increased the N content. Also, Si atoms were preferentially sputtered, and local atomic ordering was decreased, because the effect of ion bombardment was markedly enhanced. It was concluded that these characteristics contributed to the suppression of P diffusion via interstitial sites.

A.Hirata, K.Machida, S.Maeyama, Y.Watanabe, H.Kyuragi: Japanese Journal of Applied Physics - 1, 1998, 37[3B], 1251-5