 Photolithography involves exposing a light source to a photoresist-coated silicon wafer; a mask with the desired pattern is place between the light source and the wafer, thereby selectively allowing light to filter through and create the pattern on the photoresist.Further development of the wafer brings out the pattern in the photoresist.Photolithography performed in the near-UV is often viewed as the standard for fabricating topographies on the micro-scale.