Inline Monitoring is the systematic measurement of wafers at key process steps during production — using non-destructive metrology tools to track film thickness, CD, overlay, defects, and electrical parameters throughout the fabrication flow.

Key Inline Measurements

• Film Thickness: Ellipsometry or reflectometry at CVD, oxidation, and deposition steps.
• Critical Dimension: OCD or CD-SEM after lithography and etch steps.
• Overlay: Overlay metrology after lithography alignment.
• Defects: Laser scanning and SEM review after critical process steps.
• Sheet Resistance: Four-point probe or eddy current after implant and anneal.

Why It Matters

• Yield Assurance: Early detection of out-of-spec conditions prevents yield loss downstream.
• SPC: Statistical Process Control charts track inline measurements for trend detection.
• Disposition: Inline data determines whether lots proceed, are reworked, or are scrapped.

Inline Monitoring is the manufacturing health check — measuring wafers at every critical step to catch problems before they become yield killers.