Gate Bridge to Drain Contact Characteristic in Floating Gate Memory

Gate-to-drain contact short issue in floating gate memory has been studied. Two cases will be discussed, floating-gate to drain contact short, and control-gate to drain contact short, both caused by leakage bridge defect. The abnormal electrical device characteristic combined with modeling gives further insight into the failure mode. Nano-prober measurement results not only provide an evidence of short-contact issue but also measures the current behaviors between drain and gate in floating gate configuration. These results help to predict the defect location and successfully monitor the bridge-failure through electrical analysis.