Subhalf-micron lithography system with phase-shifting effect

We propose in this paper a new imaging technology for the 64M DRAM, named "CQUEST” (Canon Ql/adrupole Effect for Stepper Technology). CQUEST is derived from the mathematical analysis of the partial coherence theory1. It can provide almost the same effects with conventional masks as those that result using phase shift masks. Therefore, it is a promising candidate for next generation lithography. Simulation and some experimental results will be shown to substantiate the above. As shown in the results, the 64M DRAM process can be achieved with the existing i-line technology.