Systems having light source with extended spectrum for semiconductor chip surface topography metrology

A system for classifying interference signals, comprising:

• an interferometer comprising a light source and a detector, the interferometer configured to provide a plurality of interference signals each corresponding to a respective one of a plurality of positions on a surface of a semiconductor chip, wherein each of the interference signals comprises an interference fringe having a width not greater than about 2 μm;
• and
• at least one processor configured to:
• cluster the plurality of interference signals into a plurality of clusters using a model;
• and
• adjust the plurality of clusters into a plurality of categories based on a design of the semiconductor chip, wherein the plurality of categories are associated with interference signal classification, and wherein each of the plurality of categories corresponds to a region having a same material on the surface of the semiconductor chip.

A system for classifying spectrum signals, comprising:

• an interferometer comprising a light source and a detector, the interferometer configured to provide a plurality of interference signals each corresponding to a respective one of a plurality of positions on a surface of a semiconductor chip, wherein a spectrum of the light source is greater than a spectrum of white light;
• and
• at least one processor configured to:
• transform the plurality of interference signals into a plurality of spectrum signals each corresponding to a respective one of the positions on the surface of the semiconductor chip;
• cluster the plurality of interference signals into a plurality of clusters using a model;
• and
• adjust the plurality of clusters into a plurality of categories based on a design of the semiconductor chip, wherein the plurality of categories are associated with interference signal classification, and wherein each of the plurality of categories corresponds to a region having a same material on the surface of the semiconductor chip.