Consideration of chemical-bond configurations for radiation-hard UHV ECR-CVD SiNx x-ray mask membrane

In this paper, the chemical study on the radiation-hard silicon nitride X-ray mask membrane prepared by an ultrahigh-vacuum electron cyclotron resonance chemical vapor deposition is presented. Silicon nitride film with higher nitrogen content showed a degraded radiation-stability. It is speculated that the higher electronegativity and the stress induced by smaller covalent radius of nearest-neighbor nitrogen atoms weakens the Si-H bonds, which is the most possible source of radiation-induced damage. Increases in silicon content in silicon nitride film is supposed to result in an improvement in the radiation stability through the modification in the bandgap structure and the microscopic bond configurations.