Throughput improvement in photolithography processing for flexible production

During the drastic product change from memory devices to discrete devices, we have made various technical improvements in photolithography processing corresponding to its design characteristics, as follows: (1) establishment of fine gate processing technology; (2) optimization of throughput and processing accuracy using new photoresist processing customized for each step; and (3) establishment of flexible stepper application methods aimed at products-change-free production. Consequently, we have obtained the following beneficial results: (1) processing of 0.25 /spl mu/m discrete devices has been set up without KrF lithography; (2) a 198% improvement in stepper throughput has been achieved; and (3) a 58% reduction of waiting time has been obtained.