Cyclic deposition of silicon nitride based dielectric films

Abstract

A method for depositing silicon nitride (SiN) films within high aspect ratio (HAR) features with a reduced number of deposition cycles is provided. The method includes depositing three layers, for example, a silicon seed / silicon nitride / a silicon cap. The silicon seed and cap layers demonstrate improved bottom deposition performance with minimum sidewall and top deposition relative to silicon nitride. The silicon seed layer fills a portion of the HAR feature thus reducing the number of silicon nitride cycles needed to fill the HAR feature to targeted levels. The silicon cap layer protects the deposited silicon nitride during subsequent etching processes, which are performed to remove silicon nitride material formed on sidewalls and top surface of the feature.

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