Photolithography is the process of transferring a pattern from a mask to the substrate.
The goal is to expose parts of the wafer to the subsequent processing step while protecting the rest of the wafer. This step involves exposure to a number of organic solvents that are all dangerous if you get in contact with them. The MSDS sheets for all of these chemicals can be found in the yellow MSDS binder outside of Meyer 425. These solvents have a high vapor pressure and should be handled exclusively in the fume hood. Materials that are contaminated with photoresist are disposed of in the solid waste containers.