The effect of rapid thermal annealing on the composition, structure, andI‐Vcharacteristics of Al(0.8% Si)/Ti:W/a‐Si contacts was studied. It was established that heat treatments in temperatures ranging between 300 and 500 °C for a time span of 10 s led to grain boundary diffusion of Si and Al through the Ti10W90layer. Subsequently, Si diffused into the Al film while Al penetrated into the amorphous Si. No silicides or intermetallic compounds were observed to form as a result of the rapid heat treatments. The electrical measurements showed that theI‐Vcurve in the forward bias is identical to that of the reversed bias. The electrical resistance of the contacts increased as a result of a rise in the heat treatment temperature. A model of electrical conductivity in amorphous semiconductors was applied to explain the electrical behavior of the contacts.