3D Microscope And Methods Of Measuring Patterned Substrates
A three-dimensional (3D) microscope for patterned substrate measurement can include an objective lens, a reflected illuminator, a transmitted illuminator, a focusing adjustment device, an optical sensor, and a processor. The focusing adjustment device can automatically adjust the objective lens focus at a plurality of Z steps. The optical sensor can be capable of acquiring images at each of these Z steps. The processor can control the reflected illuminator, the transmitted illuminator, the focusing adjustment device, and the optical sensor. The processor can be configured to capture first and second images at multiple Z steps, the first image with the pattern using the reflected illuminator and the second image without the pattern using one of the reflected illuminator and the transmitted illuminator.
1 . A 3D microscope for patterned substrate measurement, the 3D microscope comprising:
an objective lens;
a reflected illuminator configured to provide reflected light for a sample including a patterned substrate and to project an image of a patterned article onto and remove the image of the patterned article from a focal plane of the objective lens;
a transmitted illuminator configured to provide transmitted illumination for the sample;
a focusing adjustment device for automating objective lens focus adjustment at a plurality of Z steps;
an optical sensor capable of acquiring images at each Z step; and
a processor for controlling the reflected illuminator, the transmitted illuminator, the focusing adjustment device, and the optical sensor, the processor configured to capture first and second images at multiple Z steps, the first image with the pattern using the reflected illuminator and the second image without the pattern using one of the reflected illuminator and the transmitted illuminator.
2 . The 3D microscope of claim 1 , wherein the patterned article is a piece of glass with a pre-determined pattern thereon.
3 . The 3D microscope of claim 1 , wherein the optical sensor includes one of a charge-coupled device (CCD) camera and a complementary metal-oxide semiconductor (CMOS) camera.
4 . The 3D microscope of claim 1 , wherein the transmitted illuminator is a light emitting diode (LED) and one of a lens and a lens group.
5 . The 3D microscope of claim 1 , wherein the focusing adjustment device is one of a motorized mechanical Z stage and a piezo Z stage.
6 . The 3D microscope of claim 5 , wherein the motorized Z stage includes one of a lead screw and a ball screw coupled to a linear bearing.
7 . The 3D microscope of claim 5 , wherein the piezo Z stage is mounted on one of a sample chuck and a microscope turret.
8 . A method of designing a 3D microscope for measurement, the method comprising:
providing an objective lens;
providing a reflected illuminator configured to provide reflected light for a sample and project an image of a patterned article onto and remove the image of the patterned article from a focal plane of the objective lens;
providing a transmitted illuminator configured to provide transmitted illumination for the sample;
providing a focusing adjustment device for automating objective lens focus adjustment at a plurality of Z steps;
providing an optical sensor capable of acquiring images at each Z step; and
providing a processor for controlling the reflected illuminator, the transmitted illuminator, the focusing adjustment device, and the optical sensor, the processor configured to capture first and second images at multiple Z steps, the first image with the pattern using the reflected illuminator and the second image without the pattern using one of the reflected illuminator and the transmitted illuminator.
9 . The method of claim 8 , wherein the patterned article is a piece of glass with a pre-determined pattern.
10 . The method of claim 8 , wherein the optical sensor includes one of a charge-coupled device (CCD) camera and a complementary metal-oxide semiconductor (CMOS) camera.
11 . The method of claim 8 , wherein the transmitted illuminator is a light emitting diode (LED) and one of a lens and a lens group.
12 . The method of claim 8 , wherein the focusing adjustment device is one of a motorized mechanical Z stage and a piezo Z stage.
13 . The method of claim 12 , wherein the motorized Z stage includes one of a lead screw and a ball screw coupled to a linear bearing.
14 . The method of claim 12 , wherein the piezo Z stage is mounted on one of a sample chuck and a microscope turret.