Neural networks as a statistical model for optical scatterometry

The advancement of new lithography techniques, such as electron-beam lithography and x-ray lithography, has enabled the fabrication of diffractive optical elements (DOEs) with feature sizes of the order of hundreds of nanometers and even less. There is also a continuous trend towards smaller line widths and higher packaging densities in memory cells and other semiconductor devices. Most of the elements are still done successfully by UV lithography which is still in the development stage in the deep UV region.