Rapid root cause analysis and process change validation with design-centric volume diagnostics in production yield enhancement

Abstract

Identifying systematic failure mechanisms that cause significant yield loss is a primary yield ramp activity. This task is rendered especially difficult for products made with sub-onehundred nanometer technologies due to the subtle design-process interactions that create transient systematic failure mechanisms. The impact of this difficulty is felt in prolonged ramp cycles and missed market windows for advanced products. A volume diagnostics methodology proposed earlier was seen to resolve this difficulty with highly accurate localization of systematic failures within the design and with an order of magnitude faster time to results compared to traditional approaches. This work presents a few examples of the success of the design-centric volume diagnostics approach in identifying subtle design-process interactions that led to systematic yield loss. It also demonstrates the statistical validation of the process changes introduced to eliminate this yield loss.

Hard to find, easy to find systematics; just find them

“…Espe cially useful are the techniques that utilize layout information to improve the resolution and accuracy of logic diagnosis [15] and for identifying layout-specific systematic defects [13,16]. Volume diagnosis has been used to find systematically fail ing standard cells [7,9,14], or specific design features of in terest [13]. More recently, statistical analysis techniques that mine the volume diagnosis results for systematically failing design features have been reported [16].…”

“…Volume logic diagnosis has been a much researched topic in the test community in the last decade [9,[12][13][14]. Espe cially useful are the techniques that utilize layout information to improve the resolution and accuracy of logic diagnosis [15] and for identifying layout-specific systematic defects [13,16].…”