Engineers need to analyze defects and other failures during microfabrication in order to troubleshoot, adjust, and improve microfabrication processes. Unfortunately, the defect characterization provided by conventional systems (e.g., optical inspection tools) is typically inadequate. The defect analysis process is typically slow and manual, and is often performed in a laboratory located outside of the cleanroom environment. Also, when a wafer is taken for detailed defect analysis, in many cases the wafer must be discarded after it has been analyzed for fear of contamination, even though only a small part of the wafer is destroyed by the analysis. With ever increasing wafer sizes and material process complexities, such losses can result in significant financial hardships.
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The present invention provides methods, devices, and systems for analyzing defects in an object such as a semiconductor wafer. The process is partially or fully automated and can be done in the wafer fabrication facility to provide rapid feedback.
In this embodiment, a defect analysis system (A) is connected to remote interface computers (B) through a network (C). The defect analysis system generally includes a defect analyzer computer (D) connected to (or integrated with) a dual-beam defect analyzer (E) and database system (F).
The dual-beam system uses an ion beam that is either normal or tilted by a few degrees to the plane of the work piece surface and an electron beam having an axis that is also tilted (e.g., 52 degrees from the axis of the ion beam). The ion beam is typically used to image and machine the work piece, and the electron beam is used primarily for imaging but can also be used for some modification of the work piece. The electron beam will typically produce an image of a higher resolution than the ion beam image, and it will not damage the viewed surface. The image formed by the two beams can look different, and the two beams can therefore provide more information than a single beam.
The DA computer and dual-beam system use software (G) for implementing defect analysis and characterization. The software includes: user interface components (H), which generate screen interfaces for presenting to users controllable access to the functions provided by the other components; a defect analyzer application/system (I), which controls the overall operation of the defect analyzer system and invokes the various other applications and tool components upon receiving requests from users; a job builder application (J), which allows users to create “jobs” that define the defect analysis and review the tasks to be performed on defect sites within one or more wafers; a sequencer application (K), which triggers the defect analysis system to perform the job tasks on the designated defect sites; a defect explorer application (L), which allows users to selectively review images and data obtained from the defect analysis; and tool components (M).
Any suitable software applications, modules, and components may be used for implementing the software.
Patent number: 7,103,505
Date: September 5, 2006
Inventors: Janet Teshima (Hillsboro, OR); Daniel E. Partin
For a detailed description of this invention, visit the U.S. Patent and Trademark Office Web site at www.uspto.gov.