DEFECTS AT THE SI SIO2 INTERFACE - THEIR NATURE AND BEHAVIOR IN TECHNOLOGICAL PROCESSES AND STRESS/

The electronic properties of silicon surfaces and interfaces are chara cterized by charges and gap states whose densities and distributions c an be strongly influenced by preparation conditions and technological treatments. A defect model for the Si/SiO2 interface considers stretch ed silicon-silicon bonds and silicon dangling-bond centres with differ ent back bond configurations connecting each kind of these defects wit h a specific energetically distributed group of interface states. The defect model was proved to be appropriate also for real silicon surfac es investigating their state distributions depending on cleaning proce dures and during native oxide growth. The state density of real and ox ide-passivated silicon surfaces can be drastically reduced by saturati on of silicon dangling bonds with hydrogen. Interfacial Si-H bonds and weak Si-Si bonds give rise to instability phenomena in connection wit h stress treatments including radiation effects.