The surface potential of ultrathin (1-3 nm) silicon-dioxide layers upon silicon substrate has been measured by vibrating capacitor (Kelvin) method. By illuminating the surface of the ultrathin SiO2Si system, a change of some hundreds of millivolts in the work function difference has been observed. After switching off the light the original (dark) value of the work function is reached through a transient process. The time constant of this transient process increases very strongly with increasing oxide thicknesses. Analysing the transient process the native oxide growth can be observed. Other oxides (e.g. that has been prepared in boiling nitric acid and thermally grown oxides) have also been investigated.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Electrical and Electronic Engineering
- Materials Chemistry