Loading patent…
AssigneeInternational Business Machines Corporation
InventorsChristopher P. Ausschnitt, Christopher J. Progler
Estimating the term…
Optical measurement of image shortening on a lithographically formed minimum feature is enhanced using crossed-polarizer imaging. The minimum feature, which is comprised of a nested array of lines having a width and space corresponding to the critical dimension of interest, is caused to maintain a preferred optical polarization axis due to the repeating nature of the nested pattern. The preferred optical polarization axis causes the transfer of some of the linearly polarized illumination into a new polarization orientation which is sympathetic with a crossed polarizer located in the detection channel of the optical imaging system. The crossed polarizer then allows the light reflected from the nested feature to pass to a detector, while extraneous (background) light is rejected. This results in a high contrast image of the nested feature that facilitates the determination of width, and that reduces measurement variability as a function of the optical properties of the nested feature.
An apparatus for optically measuring line end shortening in a nested line pattern formed on a substrate, comprising:
A method for optically measuring line end shortening in a nested line pattern formed on a substrate, using an optical tool having a source of illumination and a detector, the method comprising the steps of:
A method for monitoring bias, in a feature formed on a substrate, using an optical tool having a source of illumination and a detector, the method comprising the steps of:
A method for monitoring bias, in a feature formed on a substrate, using an optical tool having a source of illumination and a detector, the method comprising the steps of:
Dependencies are inferred from the claim text.