Endpoint optimization for semiconductor processes

US12412789B2 · kind B2 · utility

Assignee

• Applied Materials, Inc. · US

Inventors

• Avishay Vaxman · Albany, US
• Qintao Zhang · Mount Kisco, US
• Jeffrey P. Koch · Austin, US
• David P. Surdock · Kalispell, US
• Wayne R. Swart · Tivoli, US
• David J. Lee · Poughkeepsie, US
• Samphy Hong · Saratoga Springs, US
• Aldrin Bernard Vincent Eddy · Halfmoon, US
• Daniel G. Deyo · West Hurley, US

Key dates

• Filing date: Oct 14, 2022
• Grant date: Sep 9, 2025
• Expiry date: Mar 19, 2044

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01L22/12
• WIPO field: Audio-visual technology
• WIPO sector: Electrical engineering

Abstract

A camera may capture reflected light from the surface of the wafer during a semiconductor process that adds or removes material from the wafer, such as an etch process. To accurately determine an endpoint for the process, a camera sampling rate and light source intensity may be optimized in the process recipe. Optimizing the light source intensity may include characterizing light intensities that will be reflected from the waiver using an image of the wafer. Pixel intensities may be used to adjust the light source intensity to compensate for more complex wafer patterns. Optimizing the camera sampling rates may include nondestructively rotating a view of the wafer and converting the sampled intensities to the frequency domain. The camera sampling rate may be increased or decreased to remove spatial noise from the image without oversampling unnecessarily. These optimized parameters may then generate a clean, repeatable trace for endpoint determination.