Dark-field semiconductor wafer inspection device
AssigneeAltatech Semiconductor
InventorsPhilippe Gastaldo, Frederic Pernot
Life of this patent
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Abstract
The invention relates to a dark-field semiconductor wafer inspection device including, in the following order, a light source for emitting an incident beam to a wafer along a first axis, a concentrator that is symmetrical in relation to a plane passing through the first and second axes and is provided with a mirror that is elliptically cut along a plane perpendicular to an axis perpendicular to the first axis and has a generator parallel to the first axis, parallel first and second slits being set up sideways in first and second portions of the concentrator at the points for concentrating the light that is scattered by the wafer and reflected by the second and first portions of the concentrator, respectively, and a photomultiplier using a slit.
Claims12
A device for inspecting semiconductor wafers, comprising, in this order:
- a light source for emitting an incident beam toward a wafer along a first axis;
- a concentrator that is symmetrical relative to a plane passing through the first axis and a second axis perpendicular to the first axis and provided with a cylindrical mirror having an elliptical cross-section along a plane perpendicular to the second axis, and having a generatrix parallel to the first axis;
- first and second parallel slits being made laterally in first and second portions of the concentrator at concentration points of the light scattered by the wafer and reflected by the second and first portions of the concentrator respectively;
- and
- one photomultiplier per slit.
A set of two devices for inspecting semiconductor wafers, positioned facing each other in order to simultaneously inspect both faces of a wafer with different incident beam wavelengths, wherein each device comprises, in this order:
- a light source for emitting an incident beam toward a wafer along a first axis;
- a concentrator that is symmetrical relative to a plane passing through the first axis and a second axis perpendicular to the first axis and provided with a cylindrical mirror having an elliptical cross-section along a plane perpendicular to the second axis, and having a generatrix parallel to the first axis;
- first and second parallel slits being made laterally in first and second portions of the concentrator at the concentration points of the light scattered by the wafer and reflected by the second and first portions of the concentrator respectively;
- and
- one photomultiplier per split.
Dependencies are inferred from the claim text.