Mechanical Behavior of Contact Aluminum Alloy

摘要

We report the results of tensile tests of thin films of Al-0.5 % Cu deposited on bare silicon. This material was subjected to the complete CMOS fabrication process, including a high-temperature heat treatment. Contact metal makes the electrical connection between the metal wiring and the silicon transistors in a chip. Room-temperature values of yield strength, ultimate tensile strength, and elongation were all lower than the corresponding values found previously for pure electron-beam-evaporated aluminum films. The strengths and elongation decreased slightly as the specimen temperature was raised from 25 to 150℃. The slopes of the stress-strain curves from unloading-reloading runs were lower than the accepted Young's modulus of bulk polycrystalline aluminum. The results are interpreted with the help of scanning and transmission electron microscopy.