Si/SiO2 interfaces formed by remote plasma-enhanced chemical vapor deposition of SiO2 on plasma-processed Si substrates

This paper compares the formation of Si/SiO2 interfaces on Si(100) surfaces by two plasma-assisted processes with different C-atom removal steps: (i) by exposure to plasma-generated atomic H; and (ii) by exposure to plasma-generated atomic O. Studies of electrical characteristics and high-resolution transmission electron microscopy images have established that surface roughening, associated with the H-atom cleaning process, promotes a high midgap trap density through the creation of defect states at approximately 0.35, 0.55, and 0.75 eV above the valence-band edge, whereas exposure to atomic oxygen results in an atomically smoother surface having a lower midgap interfacial trap density, and with a single discrete trapping state at 0.35 eV.