Energy-Filtered Transmission Electron Microscope Tomography of Silicon Nanoparticles in Silicon Dioxide Deposited with High Density Plasma Chemical Vapor Deposition

High Density Plasma Chemical Vapor Deposition (HDPCVD), a variant of Plasma-Enhanced Chemical Vapor Deposition (PECVD), has demonstrated the capability of growing SiO2 layers with novel electronic properties. In particular, the structure of Si nanoparticles (NPs), in Si-rich HDPCVD SiO2 layers has been correlated with the performance of metal oxide semiconductor (MOS) memory devices [1]. There remains, however, a need to understand the underlying thermodynamics and kinetics of the HDPCVD process, especially as it relates to evolution of the size, shape, and density of Si NPs in SiO2 [2]. Such parameters as the deposition rate and the relative flow rate of reagents (e.g. SiH4 and N2O) [3], and their influence on Si NP configuration have been shown to play a vital role. In order to properly assess the influence of deposition parameters on the evolution of Si NPs, a detailed characterization of Si NP size and shape is essential. To that that end, Energy-Filtered Transmission Electron Microscopy (EFTEM) has been used to map the intensity of the 17 eV Si plasmon, in order to reveal the presence of Si NPs in the SiO2 layer [4]. Furthermore, a more complete characterization of the complex structure of the Si NPs can be achieved by EFTEM tomography, which provides a 3-dimensional (3D) view of the NP-rich regions of the SiO2 layer [5-7].