Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
8032585 | Thin Solid Films | 2018 | 32 Pages |
Abstract
A plasma-enhanced chemical vapor deposition (PECVD) was developed for the growth of highly conformal carbon-doped silicon nitride (SiCN) films with enhanced barrier properties drawing on tunable carbon contents, k-values, and wet etch rates (WER). Trisilylamine (TSA) was used as the main precursor and hexane was used as a hydrocarbon-containing additive precursor for carbon doping. At low deposition temperaturesâ¯â¤â¯400â¯Â°C, we show that this PECVD process leads to the formation of SiCN films with good conformality of approximately 91% over high aspect ratio trench nanostructures (4.2:1) with a growth rate of ~2.5 (Ã
/cycle). In particular, the role of TSA and hexane precursors on the film growth mechanism and the k-values, and WER in the composite structures has been explored. The precursors were introduced pulse-wise into the reaction chamber while plasma was excited. The WER of the film was evaluated in a buffered hydrofluoric acid etchant. The k-value and carbon concentration varied depending on the TSA/hexane supply time in the ranges of 7-4.5 and around 6-40%, respectively. Analysis showed that the hexane precursor improved the WER of deposited SiCN films by more than a factor of 100 compared to when only TSA was used. The SiCN film with a thickness of 5.0â¯nm exhibited excellent prevention of moisture diffusion into the device. Furthermore, the step coverage was improved to equivalent conformality of the plasma-enhanced atomic layer deposition (PEALD) by modifying the supply method of the Si and carbon precursors and the moisture barrier property was secured with thicknesses of <10â¯nm. In particular, the Si and carbon precursors are biased to maximize the process margin and control the film characteristics, where tuning can be easily implemented.
Related Topics
Physical Sciences and Engineering
Materials Science
Nanotechnology
Authors
Woo-Jin Lee, Yong-Ho Choa,