Re-examination of important defect complexes in silicon: From microelectronics to quantum computing

The physical properties of silicon can be controlled by defects and impurities present in the lattice, with carbon, hydrogen, and oxygen being the most important impurities. During material processing, these impurities interact with each other leading to the formation of clusters. The T-center contains two inequivalent C atoms with one of the two linked to an H interstitial atom. The I-center contains at least one C, one H, and one O atom in its structure. The M-center contains at least two C atoms and an H atom, but its exact structure has not been definitely determined. The G-center contains a C substitutional and C interstitial pair, whereas the W-center is composed of three silicon self-interstitials. Here, we re-examine the structure and the electronic properties of carbon–hydrogen and carbon–hydrogen–oxygen defects (T, M, I, G, and W-centers) as these are presently important for emerging quantum technologies. We discuss experimental work and how recent theoretical calculations have furthered our knowledge of these important centers.