Microanalysis of amorphous semiconductor films

In a previous paper /l/ it has been pointed out that electron energy loss spectroscopy in the infrared spectral region is a very sensitive tool for the study of structure and composition of thin films. Here as a further example the energy loss study of amorphous silicon films is presented. In the case of amorphous semiconductors where most of the optical and electrical properties are still strongly influenced by impurities an analytical test is substantial.Silicon films have been investigated which have been prepared by different methods and under different conditions: by evaporation, by decomposition of silane (SiH4) in a rf glow discharge and by sputtering. The influence of the substrate temperature has been studied for films produced by silane decomposition.Fig. 1 shows a typical spectrum of amorphous silicon prepared by the glow discharge method obtained by 30 keV electrons with a resolution of 3 to 4 meV.