Introduction

Abstract

The lithographic systems used in microelectronics are designed to perform two major operations: 1) create the topological pattern for an IC layer by printing the different pattern elements serially in time, and 2) simultaneously transfer a mask pattern in parallel to a sensitive layer deposited onto the wafer being processed. Creating the topological pattern is most often done to prepare the mask used in the parallel transfer operation; however, in recent years a serial pattern is more often created right on the semiconductor wafer for the purpose of fabricating prototype ICs or in the technology of custom circuits. Parallel pattern transfer can be used to set the number of copies of the masks and to form resist masks on semiconductor wafers.