Course 857 Optical Lithography

Dr. Uzodinma Okoroanyanwu is teaching this 4-day course on Optical Lithography.

Optical lithography, also called photolithography, can be described as a printing technology that eminently illustrates the perfect marriage between chemistry and optics. This is a technology that uses photons to induce chemical reactions in photoresist films (the image recording medium) and results in the transformation of the exposed part of the photoresist film relative to the unexposed part. Light/photoresist interactions lead to photochemical reactions and photophysical processes that underlie the contrast between the exposed and unexposed region of the film, and this is manifested as the latent image. This lithographic image contrast forms the basis of the printed image and underlies the usage of optical lithographic printing in transferring to the photoresist-coated wafer surface geometric patterns representing integrated circuit (IC) design information on a photomask. Other interesting attributes of optical lithography include the potential for image reduction using projection optics, use of transmission or reflective photomasks, and extremely high capacity for image information transfer on the order of terapixels per exposure shot for the latest advanced exposure tools, which makes for high throughput and high patterning fidelity.
This course examines at both introductory and advanced levels the physical and chemical basis of optical lithography.