EFFECT OF STRESS ON ALUMINUM INDUCED CRYSTALLIZATION OF MAGNETRON SPUTTERED AMORPHOUS SILICON THIN FILM

摘要

The effect of stress on aluminum-induced crystallization (AIC) of magnetron-sputtered amorphous silicon (a-Si) is investigated. Different layered structures were prepared to study the effect of stress on AIC. Pre-crystallization stress of a-Si was determined by measuring the radius of curvature of c-Si wafer substrates before and after depositing a sequence of a-Si and Al films. It was observed that as-deposited aluminum film on c-Si substrate was in tensile stress, while the a-Si film was in compressive stress. After depositing various layered structures, the final stress value for the a-Si films was measured. All the samples were then annealed for 30 minutes in the temperature range of 375℃ to 525℃ in an effort to initiate crystallization. X-ray diffraction of the samples was used to study the crystallinity of the films. It was determined that films with lower initial stress can be crystallized at lower temperatures. From the data, the minimum temperature required for AIC of a-Si was estimated.