Post-Sputtering Heat Treatments of Molybdenum on Silicon Wafer

This paper investigated the property evolutions of Mo thin films that were subjected to post-sputtering heat treatments from 700 degrees C to 1100 degrees C. It was found that, after annealing, the use of Si wafers eliminated crack formations found in previously reported Mo thin films sputtered on fused silica substrates. The recrystallization of the Mo thin film was found to start at 900 degrees C, which led to rearrangements of the preferred crystalline orientation and enhancement of grain size when the annealing temperature was further increased. The electrical conductivity of the Mo thin films was majorly affected by the increase of Mo crystallite size as the annealing temperature was increased. Overall, the improvement of material sustainability and compatibility in the high temperature annealing process has made it positive to implement a Mo-Si contact-substrate scheme for vertical structured Si QDs solar cells.