Apparatus and method for feature edge detection in semiconductor processing

A method for determining a destination for a semiconductor device substrate, comprising:

• identifying an identification mark comprising at least one recess defining a character within a surface of the semiconductor device substrate and embedded material opaque to visible wavelengths of electromagnetic radiation by:
• scanning electromagnetic radiation of at least one wavelength across at least a portion of the semiconductor device substrate including the at least one recess, the at least one wavelength capable of at least partially penetrating the material;
• measuring an intensity of radiation of the at least one wavelength reflected by different locations of the at least a portion of the semiconductor device substrate;
• detecting locations at which the intensity changes from substantially a baseline intensity;
• and
• correlating each location at which the intensity changes to identify the mark;
• and
• identifying a predetermined destination for the semiconductor device substrate based on the identification mark.

A system for identifying a marking on a substrate indicative of a type of semiconductor device being fabricated on the substrate and at least partially covered by at least one layer of material, comprising:

• at least one radiation source configured and positioned to direct electromagnetic radiation of at least one wavelength toward a substrate, the at least one wavelength capable of at least partially penetrating a material opaque to visible wavelengths of electromagnetic radiation;
• at least one reflectometer positioned so as to receive electromagnetic radiation of the at least one wavelength reflected from a location of the substrate covered with a material opaque to visible wavelengths of electromagnetic radiation;
• and
• at least one processor associated with the reflectometer for analyzing a pattern of intensities of electromagnetic radiation of the at least one wavelength reflected from a plurality of locations of the substrate and for correlating the pattern of intensities to a known identifier associated with the marking and to the type of semiconductor device being fabricated on the substrate.

A processor for characterizing at least one material-covered recessed marking formed in a substrate embedded within material opaque to visible wavelengths of radiation for identifying a type of semiconductor device being fabricated on the substrate, comprising:

• at least one logic circuit for comparing a measured intensity of at least one wavelength of reflected radiation to a baseline intensity of the at least one wavelength of radiation reflected from a planar portion of the substrate and through at least one material layer that is opaque to visible wavelengths of electromagnetic radiation;
• and
• at least one logic circuit for mapping a plurality of locations of the substrate where the measured intensity differs from the baseline intensity, the at least one logic circuit being under control of at least a portion of at least one program, a map resulting from the mapping comprising a digital image of characters of the recessed marking;
• and
• at least one logic circuit for identifying a type of semiconductor device that corresponds to the mapped locations.