Wafer appearance inspection apparatus
View Patent ↗Provided is a wafer appearance inspection apparatus that can segmentize an inspection target region, enable expedited execution of an operation to set a sensitivity threshold to each region, and enhance the inspection efficiency. Pattern matching between the image region of a part of a standard wafer, which is defined as a template region, and the entire image region of the standard wafer is performed to compute an image editing value. The computed image editing value is used to edit an inspection target image. A region for which a threshold is to be set can be automatically confirmed by roughly specifying the region from among edited image regions displayed on the display. The confirmed region and a similar pattern region are searched and displayed. When the similar region is selected, the initial sensitivity threshold is displayed, and a change is made on an as-needed basis. The region of the set sensitivity threshold is displayed by the display color corresponding to the determined threshold. Inspection is executed according to the set threshold.
1. A wafer appearance inspection apparatus comprising:
a light source that irradiates light to an inspection target wafer;
a light detector that detects light reflected from the inspection target wafer;
an image processor that converts, into an image, the light detected by the light detector;
an image display portion;
an operation portion that inputs an operational instruction; and
an operation control portion that performs:
defining, as a template image, a part of an image distortion editing wafer for which image processing is performed by the image processor;
pattern match processing with an entire image of the image editing wafer using the template image;
computing a pixel deviation of the image of the image editing wafer;
editing the image of the inspection target wafer using the computed pixel deviation;
determining an image region indicated by the operation portion;
searching an image region, a surface profile pattern of which is similar to a surface profile pattern of the determined image region, from among other image regions of the edited inspection target wafer, and displaying the searched image region on the image display portion; and
setting a sensitivity threshold for the image region indicated by the operation portion,
such that an appearance of the wafer is inspected based on the sensitivity threshold set by the operation control portion.
2. A wafer appearance inspection apparatus comprising:
a light source that irradiates light to an inspection target wafer;
a light detector that detects light reflected from the inspection target wafer;
an image processor that converts, into an image, the light detected by the light detector;
a memory that stores image data for which image conversion is performed by the image processor;
an image display portion;
an operation portion that inputs an operational instruction; and
an operation control portion that performs:
obtaining, from the operation portion, an image display region on the image display portion;
deleting, from among image data stored in the memory, image data that are not within the image display region indicated by the operation portion;
reading out image display region data indicated by the operation portion and displaying only the image display region data that are within the image display region on the image display portion;
determining a sensitivity threshold setting image region indicated by the operation portion;
searching, from among image regions displayed on the image display portion, an image region of which surface profile pattern is similar to a surface profile pattern of the determined sensitivity threshold setting image region, and displaying the searched image region on the image display portion; and
setting a sensitivity threshold to the sensitivity threshold setting image region indicated by the operation portion,
such that an appearance of the wafer is inspected based on the sensitivity threshold set by the operation control portion.
3. A wafer appearance inspection apparatus comprising:
a light source that irradiates light to an inspection target wafer;
a light detector that detects light reflected from the inspection target wafer;
an image processor that converts, into an image, the light detected by the light detector;
an image display portion;
an operation portion that inputs an operational instruction; and
an operation control portion that performs:
determining a sensitivity threshold setting image region indicated by the operation portion;
reducing the sensitivity threshold setting image region and an image region of the inspection target wafer;
defining the reduced sensitivity threshold setting image region as a template image;
pattern matching with the reduced image region of the inspection target wafer;
acquiring an matching candidate image; and
based on the acquired image, setting a sensitivity threshold to the sensitivity threshold setting image region,
such that an appearance of the wafer is inspected based on the sensitivity threshold set by the operation control portion.
4. A wafer appearance inspection apparatus comprising:
a light source that irradiates light to an inspection target wafer;
a light detector that detects light reflected from the inspection target wafer;
an image processor that converts, into an image, the light detected by the light detector;
an image display portion;
an operation portion that inputs an operational instruction; and
an operation control portion that performs:
determining a sensitivity threshold setting image region indicated by the operation portion;
defining the sensitivity threshold setting image region as a template image;
pattern matching with an image region of the inspection target wafer;
acquiring an matching candidate image; and
based on the acquired image, setting a sensitivity threshold to the sensitivity threshold setting image region, such that an appearance of the wafer is inspected based on the sensitivity threshold set by the operation control portion, wherein
the operation control portion performs:
reducing the sensitivity threshold setting image region and the image region of the inspection target wafer;
defining the reduced sensitivity threshold setting image region as a template image;
pattern matching with the reduced image region of the inspection target wafer;
acquiring a matching candidate image;
restoring an image from the acquired matching candidate image so that a size of the restored image is equal to a pre-reduction size;
pattern matching with a pre-reduction image region of the inspection target wafer;
acquiring a matching candidate image; and
based on the acquired image, setting a sensitivity threshold to the sensitivity threshold setting image region.