Crystallographic orientation dependence of compositional transition and valence band offset at SiO2/Si interface formed using oxygen radicals

Abstract

The chemical and electronic-band structures of SiO2/Si interfaces formed utilizing oxygen radicals were investigated by measuring angle-resolved photoelectron spectra arising from Si 2p and O 1s core levels and a valence band with the same probing depth. We clarified that (1) the SiO2/Si interfaces formed exhibited an almost abrupt compositional transition, (2) the valence band offsets at the Si(111)/Si, Si(110)/Si, and Si(551)/Si interfaces are almost the same and are 0.07 eV smaller than that at the SiO2/Si(100) interface.

Clear Difference between the Chemical Structure of SiO2/Si Interfaces Formed Using Oxygen Radicals versus Oxygen Molecules

“…Figure 3(a) is obtained by subtracting the Si 2p 3/2 spectrum measured at TOA of 15q from Si 2p 3/2 spectrum measured at TOA of 85q for the oxide film formed utilizing OR. This subtraction was performed, to eliminate spectrum arising from the oxide film after multiplying the spectrum measured at a TOA of 15q by an appropriate factor b [6,15]. Figure 3.…”

Angle-resolved photoelectron spectroscopy study on interfacial transition layer and oxidation-induced residual stress in Si(1 0 0) substrate near the interface

“…2) is used for the calculation of the internal TOAs. Other analytical details were described elsewhere [11]. Fig.…”

“…(3) An oxide film was prepared by the oxidation using oxygen radicals (hereafter referred as oxygen-radical oxidation) at 400°C. Here, oxygen radicals were produced in a microwave-excited high-density Kr(97%)/O 2 (3%) mixture plasma [10,11] oxidation all oxide films were kept in isopropyl alcohol solution, from which O 2 gas were removed completely, immediately after their preparation until their photoelectron spectra were measured. We measured the Si 2p spectra arising from the oxide films at the external photoelectron take-off angles (TOAs) of 10°, 15°, 20°, 30°, 52°, and 85°at the vacuum/SiO 2 interface.…”

Influence of Forming Gas Annealing on SiO2/Si(100) Interface Structures Formed Utilizing Oxygen Molecules Different from that Utilizing Oxygen Radicals

“…On the other hand, in the case of conventional thermal oxidation utilizing dry oxygen molecules (OMs), the relatively high quality oxide film was obtained only on Si(100) surface. We have found a clear difference between the chemical structure of the SiO 2 /Si interface formed using ORs and that formed using OMs (12,13). In the fabrication of Si-based semiconductor devices the interface state density at the SiO 2 /Si interface is usually reduced by forming gas annealing (FGA) (14).…”