Improvement of Base Ideality through Improved Surface Cleans

摘要

For both commercial and industrial applications, HBT intrinsic reliability requires that performance does not degrade with time. Long-term reliability has been associated with low-voltage base current, of which one source is base ideality. This paper explores factors affecting surface cleanliness and their influence on base ideality, including base metal evaporation and post-metal liftoff cleans.