Electron holography of Si:C films and Si:C-based devices

Microstructure of Si1-xCx films grown epitaxially onto Si wafers was studied. Clusters formed by Si and interstitial carbon were observed in Si1-xCx films by transmission electron microscopy. It was found that the cluster size increases with the total carbon content. Electron holography has determined that clusters are negatively charged. Devices were fabricated with in situ phosphorus doped Si1-xCx films grown in the source-drain regions. It was found that the Si1-xCx regions are negatively charged and the phosphorus dopant is partially activated. The results provide insight into formation of the Si1-xCx epitaxial films and design of devices based on these films.