Abstract
Utilizing a thick planarizing layer at the bottom and a thin imaging layer on top, multilayer resist systems offer improvements in sensitivity, linewidth control, height-to-width aspect ratio of the resist image, manipulation of the resist image profile, focus tolerance, proximity effects, and charging effects, in optical, e-beam, x-ray, and ion-beam lithography. The particular improvements related to each imaging means are discussed and illustrated, showing that with all known imaging means, multilayer resist systems can indeed improve lithographic performance.