SPIE - Education Practical Photoresist Processing SC616

Photolithography is the technique underlying all integrated circuit manufacture. To a large extent, the minimum feature size and the performance of ICs is determined by the resolution achievable in this step. Also, the process yield has a strong impact on a Fab's economy. The troubleshooting of photoresist performance is therefore a key concern to every microlithography engineer. However, this requires a highly interdisciplinary understanding of many areas, from photochemistry to polymer science to optics, that are usually not taught in a unified way in most educational curricula. In this course, photoresist processing is examined by walking a wafer through the lithographic sequence, beginning with the wafer preparation and ending when the resist feature has been prepared for dry etching. Both classic near-UV DNQ/novolak resists as well as chemically amplified systems (248 and 193 nm as well as EUV) will be covered. The chemical changes occurring in photoresists during the different process steps will be discussed. Pitfalls and failure modes will be pointed out at every step and correlated to the underlying properties of the photoresist materials. The aim of the course is to give microlithography engineers a practical basis from which to begin the detective work involved in identifying the root cause of a processing problem.