Abstract
A process to produce high-aspect-ratio resist images using the portable conformable masking (PCM) technique is described. It is known that the vertical dimension of semiconductor devices in integrated circuits does not scale linearly with the lateral dimensions. Therefore, when the lateral dimension approaches 1 mu m, it is often necessary to produce 2 mu m high resist images for the vertical structure. This type of aspect ratio is difficult to achieve using a single layer of resist with optical projection printing or E-beam writing. The PCM technique using a thin resist on a thick resist amplifies the aspect ratio by deep-UV imaging the bottom resist through the patterned thin resist layer.