Modeling the effect of oxygen on vapor phase diamond deposition inside micro-trenches

Abstract

For the same feed gas composition, radical species concentrations vary with depth inside micro-trenches during diamond deposition. However, the feed gas compositions are typically used for predicting diamond deposition vs. non-diamond deposition. So, any type of modeling for predicting diamond deposition quality and uniformity inside trenches and onto three-dimensional objects is not possible. In this regard, a simple modeling approach utilizing a recently constructed C–H–O ternary diagram, based on radical species composition by Eaton and Sunkara [Eaton and Sunkara, Diam. Relat. Mater., 9 (2000) 1320], demonstrated the diamond deposition process inside trenches. Specifically, the effect of oxygen in the feed gases on the depths at which diamond can be deposited is modeled under both Knudsen and Fickian diffusion conditions and compared with experimental observations. The results suggested that certain feed gas phase compositions (C/O ratio) help increase the aspect ratio (>2.0) at which diamond deposition can be achieved.