Device and method for inspecting semiconductor wafers
AssigneeAltatech Semiconductor
InventorPhilippe Gastaldo
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Abstract
The invention relates to a device for inspecting the edge of semiconductor wafers, including a chromatic confocal microscope (7) with a lighting pathway (10) and an analysis pathway (20), the lighting pathway (10) including a polychromatic light source (11), a slot (12) and an axial chromatism objective lens (15) comprising a lens at least made of a material having an Abbe number lower than 50, and the analysis pathway (20) includes said objective lens, a chromatic filtering slot (22) with a light intensity sensor (24) in that order, the slot of the lighting pathway and the slot of the analysis pathway being provided at substantially the same optical distance from the edge of the wafer to be inspected.
Claims15
Device for inspecting the edges of semiconductor wafers, comprising:
- a confocal chromatic microscope provided with a lighting pathway and an analysis pathway, the lighting pathway comprising a polychromatic light source, a slot and an objective lens with axial chromatism comprising at least one lens made of a material having an Abbe number of less than 50, and the analysis pathway comprising the said objective lens, a chromatic filtering slot and a light intensity sensor in that order, the slot of the lighting pathway and the slot of the analysis pathway being arranged substantially at the same optical distance from the edge of the wafer to be inspected.
Device according to one of the preceding claims, wherein the said objective lens has an optical diameter of less than 100 mm.
Process for inspecting the edges of semiconductor wafers, wherein the said edge is illuminated by a polychromatic light source, the incident beam passing through a slot and through an objective lens wherein the materials of at least one lens have a chromatic aberration with an Abbe number of less than 50, and the reflected beam is collected after it has passed through said objective lens then through a chromatic filtering slot configured to spatially filter the wavelengths not focused on the edge of the semiconductor wafer, the collection being carried out by a light intensity sensor.
Dependencies are inferred from the claim text.