Process materials (gases and chemicals)
What purity is typically required for copper sputtering targets used for seed layers?
- AHigh purity of about 6N (99.9999%)
- BAbout 90%
- CAbout 50%
Show answer and explanation
Answer: A. High purity of about 6N (99.9999%)
Impurities in sputtering targets are incorporated directly into the film, affecting wire resistance and reliability. Copper targets therefore require high purity of about 6N. The size and orientation of their grains are also controlled to improve film uniformity.