Metal layer oxide void leading to a reliability failure

This paper will present a unique oxide void found in Flash memory products where the oxide void is present in between metal layers which does not show any functional issues initially but degrades over time and leads to a reliability failure. This is problematic because the defect is not easily detectable by the inline inspection and cannot be screened by the initial electrical functional test either while it takes time to cause functional issues later. While this paper also touches on the detection and screening of the defect, a careful validation at the process design stage is critical to prevent this type of failure mode.