Rutherford backscattering thin-film analysis

The remaining work discusses two techniques in thin film analysis, Rutherford backscattering spectrometry (RBS) and X-ray diffractrometry with emphasis on strain measurements. Rutherford backscattering spectrometry is illustrated with analysis of silicide formation as an example of thin film reactions. Silicon-germanium-carbon films serve as an example of strain calculations. 

This paper describes a process for activating polyimide surfaces for electroless metal plating. A thin surface region of a polyimide film can be electro-chemically reduced when contacted with certain reducing agent solutions. The electroactivity of polyimides is used to mediate electron transfer for depositing catalytic metal (e.g., Pd, Pt, Ni, Cu) seeds onto the polymer surface. The proposed metal deposition mechanism presented is based on results obtained from cyclic voltammetric, UV-visible, and Rutherford backscattering analysis of reduced and metallized polyimide films. This process allows blanket and full-additive metallization of polymeric materials for electronic device fabrication. 

The application of ion beam analysis techniques to determine pore size and pore volume or density of thin silica gel layers was first described by Armitage and co-workers [114]. These techniques are non-destructive, sensitive and ideally suited for the analysis of thin porous films such as membrane layers (dense support is needed for backscattering). However, apart from a more recent report on ion-beam analysis of sol-gel films [115] using Rutherford backscattering and forward recoil spectrometry, ion beam techniques have not been developed further despite their potential for membrane characterisation. This is probably due to the limited availability of ion beam sources, such as charged particles accelerators. 

Rutherford backscattering spectrometry analysis determines how the composition varies as a function of depth and is used to characterize thin films and thin film reactions. During ion-beam analysis, the incident particle (typically a proton or helium ion) penetrates into the thin film and undergoes inelastic collisions, with target electrons, and loses energy as it transverses the sample. 

The essentially non-destructive nature of Rutherford backscattering spectrometry, combined with the its ability to provide both compositional and depth information, makes it an ideal analysis tool to study thin-film, solid-state reactions. In particular, the non-destructive nature allows one to perform in situ RBS, thereby characterizing both the composition and thickness of formed layers, without damaging the sample. Since only about two minutes of irradiation is needed to acquire a Rutherford backscattering spectrum, this may be done continuously to provide a real-time analysis of the reaction [6]. 

Various methods of analyzing surfaces for chanical composition and physical texture. Electron spectroscopy for chemical analysis and Auger analysis [19] are techniqnes that have been used to identily chemical species in thin films. In Rutherford backscattering spectrometry incident He ions are scattered elastically by nuclei. The energy spectrum thus obtained can... 

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