Study on the crystallization of amorphous Cr-Si-Ni thin films using in situ X-ray diffraction

Crystallization behavior of amorphous Cr-Si-Ni thin films was investigated by means of high temperature in situ X-ray diffraction measurements. The di ffraction spectra were recorded isothermally at temperature between 250 and 750 degreesC. The in situ testing of crystallization enables the direct ob servation of structure evolution which is dependent on heat treatment. Base d on the testing results, the grain sizes of the crystalline phases were co mpared and phase transition tendency was understood. In the mean time, elec trical properties of the films as functions of annealing temperature and ti me have been studied. The increase of volume fraction of CrSi2 crystalline phases in the Cr-Si-Ni films leads to the decrease in conductivity of the f ilms. The annealing behavior of temperature coefficient of resistance (TCR) is a result of competition between a negative contribution caused by the w eak localization effects in amorphous region and a positive contribution ca used by CrSi2 grains. Thus the proper mixture of amorphous and crystalline constituents could result in a final zero TCR.