Screen Shot for Calibrate

[Stanford Imaging Inc.]

OCR Screen Shot

In this example, we used the Windows interface demo program to run the SII WaferID function “OCR”, using the recipe. The image captured contains not only the wafer ID string, but also patterned areas above it and to its left side. The patterned areas are very prominently bright in this Dark Field view. However, in the Bright Field view, the Wafer ID string is completely invisible on this wafer, so the user is has to use this view. Despite these challenges, the SII WaferID system reads the Wafer ID string easily, with quality scores ranging from 80 (for the character “2”, second character from the right) to 92 (for the character “1”, the first character on the left). The overall score for the string is 84.7, and the orientation angle for the string is –1.3 degrees (i.e. 1.3 degrees clockwise from the horizontal). Note that the third character from the left in this string is constrained by the recipe to be a hyphen (the third character in the “Field Constraints” string is “-“, so the score for that character is set to 100.

[OCR Screen Shot]