Multi-surface specular reflection inspector
First Claim
1. An optical inspector, comprising:
- a time varying beam reflector;
a radiating source that irradiates the time varying beam reflector;
a telecentric scan lens configured to direct the radiation reflected by the time varying beam reflector onto a first surface of a transparent sample, wherein a portion of the radiation irradiates a second surface of the transparent sample;
a first detector configured to receive at least a portion of top surface specular reflection and generate a first detector output signal, wherein the top surface specular reflection results from the irradiation of the first surface of the transparent sample;
a second detector configured to receive at least a portion of the bottom surface specular reflection and generate a second detector output signal, wherein the bottom surface specular reflection results from the irradiation of the second surface of the transparent sample; and
a processor that determines that a defect is present on the top surface or the bottom surface of the transparent sample using only two detector output signals;
(i) the first detector output signal, and (ii) the second detector output signal.
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Accused Products
Abstract
An optical inspector includes a time varying beam reflector, a radiating source that irradiates the time varying beam reflector, a telecentric scan lens configured to direct the radiation reflected by the time varying beam reflector onto a first surface of a transparent sample, a first detector that receives at least a portion of top surface specular reflection, a second detector that receives at least a portion of the bottom surface specular reflection. A turning mirror may also be included. The turning mirror is a switchable mirror that can be adjusted to a first position where the turning mirror reflects the top and bottom surface specular reflection, and can be adjusted to a second position where the turning mirror does not reflect the top or the bottom surface specular reflection. A first and second polarizing element may also be included to detect additional types of defects on either surface.
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Citations
20 Claims
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1. An optical inspector, comprising:
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a time varying beam reflector; a radiating source that irradiates the time varying beam reflector; a telecentric scan lens configured to direct the radiation reflected by the time varying beam reflector onto a first surface of a transparent sample, wherein a portion of the radiation irradiates a second surface of the transparent sample; a first detector configured to receive at least a portion of top surface specular reflection and generate a first detector output signal, wherein the top surface specular reflection results from the irradiation of the first surface of the transparent sample; a second detector configured to receive at least a portion of the bottom surface specular reflection and generate a second detector output signal, wherein the bottom surface specular reflection results from the irradiation of the second surface of the transparent sample; and a processor that determines that a defect is present on the top surface or the bottom surface of the transparent sample using only two detector output signals;
(i) the first detector output signal, and (ii) the second detector output signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
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17. An optical inspector, comprising
a time varying beam reflector; -
a radiating source that irradiates the time varying beam reflector; a lens configured to direct the radiation reflected by the time varying beam reflector onto a first surface of a transparent sample, wherein a portion of the radiation irradiates a second surface of the transparent sample; a first means for separating top surface specular reflection from bottom surface specular reflection, wherein the top surface specular reflection results from the irradiation of the first surface of the transparent sample, and wherein the bottom surface specular reflection results from the irradiation of the second surface of the transparent sample; a second means for measuring an intensity of the top specular reflection and an intensity of the bottom specular reflection; and a processor that determines on which surface a defect is present, wherein the determining only uses two intensity measurements;
(i) the measured intensity of the top specular reflection, and (ii) the measured intensity of the bottom specular reflection. - View Dependent Claims (18, 19, 20)
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Specification