Journal of Vacuum Science & Technology B, Vol.24, No.6, 2892-2896, 2006
Arrayed miniature electron beam columns for mask making
A significant problem facing integrated circuit mass-production lithography at future technology generations is the throughput of mask writers. Novelx has developed the technologies to build a distributed multiaxial parallel beam system consisting of a monolithic array of individually correctable electron beam columns. These technologies can be scaled to manufacture a system with a sufficient number of columns to write a single mask at the 32 nm node with a write time of an order of magnitude faster than what is forecasted at the back end of the 45 nm node. The key to these technologies is a new type of miniature electron beam column fabricated and assembled using manufacturable processes. Both single and 1 x 4 multicolumn systems have been assembled and tested, and have demonstrated 90 nm lithography. The columns in these systems operate at low voltage and are all electrostatic. The lenses are monolithically fabricated bonded stacks of micromachined silicon and glass. The monolithic lenses are assembled onto a single package. The multicolumn lens stacks consist of four independent and electrically isolated lenses. The silicon and package are scalable for continued miniaturization, and can be fabricated in larger monolithic arrays of individually correctable beams. The authors show that the 1 x 4 column system currently in operation can be scaled to a 4 x 4 column system and that a mask writer using the 4 x 4 column system is capable of writing a single mask at the 32 nm dynamic random access memory 1/2 pitch node in 10 h. (c) 2006 American Vacuum Society.