3D Microscope And Methods Of Measuring Patterned Substrates

摘要

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.

主权项

1. A method of measuring a patterned substrate sample, the patterned substrate sample including a plurality of patterned substrate features, the method comprising:
varying a relative distance between the patterned substrate sample and an objective lens at predetermined steps; at one or more of the predetermined steps:
projecting an image of a patterned article onto a focal plane of the objective lens;capturing a first image with a pattern associated with the patterned article and the sample, and storing the first image in a first image array; andcapturing a second image of the sample without the pattern associated with the patterned article, and storing the second image in a second image array; using the second image array to roughly estimate a bottom position of the patterned substrate features; using the roughly estimated bottom position and the second image array to identify first locations of the patterned substrate sample that do not include the plurality of patterned substrate features; using the first image array and the first locations to accurately determine the bottom position of the patterned surface features; using the accurately determined bottom position and the second image array to identify second locations of the patterned substrate sample that include the plurality of patterned substrate features; determining a top of each patterned substrate feature based on the second locations and one of the first image array and the second image array; and calculating geometric parameters of patterned substrate features using the second locations, the accurately determined bottom position, and the top of each patterned substrate feature.