1. Ammonia plasma immersion ion implantation into silicon: Composition and structure of the resulting silicon–nitrogen–hydrogen system
- Author
-
Wolfgang Ensinger, Kerstin Volz, Chr. Klatt, and B. Rauschenbach
- Subjects
Nuclear and High Energy Physics ,Materials science ,Silicon ,Gate dielectric ,Analytical chemistry ,chemistry.chemical_element ,Rutherford backscattering spectrometry ,Nitrogen ,Plasma-immersion ion implantation ,Amorphous solid ,chemistry.chemical_compound ,chemistry ,Silicon nitride ,Nuclear reaction analysis ,Instrumentation - Abstract
Silicon nitride phases are of technological interest for example as gate dielectric in thin film and field effect transistors. The present study compares nitrogen with ammonia plasma immersion ion implantation (PIII) of silicon before and after an annealing step. Nitrogen, silicon and hydrogen depth profiles were obtained by Rutherford backscattering spectrometry (RBS) and nuclear reaction analysis (NRA). For ammonia plasma immersion implantation significantly higher nitrogen concentrations are obtained than for nitrogen implantation as well as the maximum of the nitrogen profile is buried. It turns out that despite the excess of H compared to N in the plasma only a maximum of 2.5 at.% of H is incorporated in a stoichiometric Si3N4 film in the as implanted state. Upon annealing, hydrogen-free silicon nitride films are obtained. The structure has been examined by transmission electron microscopy (TEM). XTEM shows that the initially amorphous SixNyH films are converted into crystalline α-Si3N4 after the annealing step.
- Published
- 2000