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AssigneeNova Measuring Instruments Ltd.
InventorsBoaz BRILL, Moshe Finarov, David Scheiner
Estimating the term…
Alignment of layers during manufacture of a multi-layer sample is controlled by applying optical measurements to a measurement site in the sample. The measurement site includes two diffractive structures located one above the other in two different layers, respectively. The optical measurements include at least two measurements with different polarization states of incident light, each measurement including illuminating the measurement site so as to illuminate one of the diffractive structures through the other. The diffraction properties of the measurement site are indicative of a lateral shift between the diffractive structures. The diffraction properties detected are analyzed for the different polarization states of the incident light to determine an existing lateral shift between the layers.
A structure configured for overlay measurement on a sample, said structure comprising at least one pair of diffractive structures of predetermined geometries and with a predetermined lateral shift between them, diffraction of incident light from said at least one pair of diffractive structures being indicative of a lateral shift between layers in the sample.
A multi-layer sample comprising at least one test site configured to allow overlay measurement to correct alignment of the layers in the sample, said at least one test site comprising at least one pair of diffractive structures of predetermined geometries arranged with a predetermined lateral shift between them, diffraction of incident light from said at least one site being indicative a lateral shift between the layers in the sample.
A multi-layer semiconductor wafer comprising a patterned area and at least one test site located outside said patterned area, said at least one test site being configured for overlay measurements to correct alignment of the layers of the semiconductor wafer within said patterned area thereof, said at least one test site comprising at least one pair of diffractive structures of predetermined geometries arranged with a predetermined lateral shift between them, diffraction of incident light from said at least one site being indicative a lateral shift between the layers in the semiconductor wafer.
Dependencies are inferred from the claim text.