Performance and perspective of the newly developed high-accuracy mask-making EB lithography system JBX-7000MV designed for 64M DRAM production

The semiconductor industry has directed its course toward volume production of 64M DRAMs. Feature sizes of typical 64M DRAM are 0.3 to 0.4 micrometers , and the linewidth and positioning accuracies required for 5X reticle production are both 0.05 micrometers . To respond to these requirements, JEOL has developed an electron beam lithography system for reticle making, JBX-7000MV, which incorporates improved variable shaped beam optics to assure high speed and highly accurate pattern writing. The high accuracy writing was made possible by: (1) reducing the pattern data increment and correction increments by 1/2; (2) applying a field shift writing method; and (3) a new substrate holder insensitive to the weight of a mask. This paper introduces the JBX-7000MV and its capabilities, and discusses the issues required for second generation 64M DRAM reticles. Anticipated improvements expected to be integrated in the JBX-7000MV to meet these requirements are discussed.