Mass Spectra Analyses of Impurities and Ion Clusters in Amorphous and Crystalline Silicon Films

Abstract

Vacuum‐deposited amorphous and crystallized silicon films were studied by sputter‐ion source mass spectrometry. Crystallization was carried out in both argon and vacuum environments. Positive impurity ions and polyatomic ions (clusters) were examined. Impurities which arose from the crucible, residual atmosphere, substrate, and structural components in the system are described. Films crystallized in the vacuum generally contained more impurities than those crystallized in an inert atmosphere. Cluster distributions or relative amount of for amorphous and crystallized samples are essentially the same. However higher order cluster peaks appear to be slightly lower in amorphous samples. The relation between cluster distribution and atomic nearest neighbor environment is discussed.