HINDERED TRANSFORMATION OF PD2GE TO PDGE IN THE PD A-GEH SYSTEM/

A comparative study of the interfacial reactions between Pd and a-Ge:H , deposited at T(S)=150-degrees-C (low temperature, LT) and at T(S)=20 0, 300-degrees-C (high temperature, HT), was carried out by x-ray diff raction and Auger electron spectroscopy after sample annealing in the regime of T=200-300-degrees-C and t=1/4-4 h. It was found that the Pd/ a-Ge:H(LT) formed a much more stable Pd2Ge interfacial layer, compared to the Pd/a-Ge:H(HT) system in which the Pd2Ge was transformed to PdG e. The main difference between the LT- and the HT-a-Ge:H films is prob ably the structure of the material. Whereas the HT films are compact, the LT-a-Ge films contain a network of voids which slow down the diffu sion of Ge to the interface.