US Patent 7360851 - Feedback adjustment for nanoimprint lithography density control

http://www.freepatentsonline.com/7360851.html

Nanoimprint lithography is a method of transferring nanoscale patterns onto a variety of substrates. This patent from KLA-Tencor teaches a particular method of nanoimprint lithography based on liquid transfer in which the density of the liquid being transferred is monitored for feedback regulation. Claim 1 reads:

1. A method for control of spreading of liquid droplets, comprising:

depositing an initial pattern of drops of a liquid on a first surface;

bringing a second surface into sufficient contact with at least a portion of the initial pattern of drops on the first surface that the liquid begins to spread; capturing one or more digital images of the liquid after it begins to spread;

performing a digital analysis of the one or more images to determine whether one or more portions of the initial pattern of drops require more liquid; and

adjusting a subsequent pattern of drops of liquid based on the digital analysis of the two or more images.