Low-energy focused ion beam (FIB) is a useful tool for shallow doping, gas-assisted etching, and other uses to minimize substrate damage in semiconductor device fabrication. The possibility to form a finely FIB of low energy under 1 keV was suggested in the investigations on the retarding mode in electron optical systems. The abilities of the simplest type of retarding mode FIB column are examined here. The optical properties are calculated for the corresponding model and some images are observed with Ga+ ion beams <0.3 μm in diameter for beam energies, 10, 5, and 1 keV, using a retarding mode one-lens FIB system. 1-keV and 100-eV Ga+ FIB was implanted to Ga/As substrate, and the defects are analyzed by deep-level transient spectroscopy. The defect concentration for 100 eV was < (1)/(5) that for 1000 keV.

Lithography (LEEPL) h2 has been developed for proof of lithography (POL) of mass production tool, which is applied to required performance in 100-nm and 70-nm technology node. Major features of system design are an acceleration voltage of 1-5 kV, a beam current of 3-20 µA, a maximum field size of 40 mm x 40 mm (effective field size of 25 mm x 25 mm), a die-by-die alignment system and automatic loader systems for masks and wafers. The throughput is estimated over 20 wafers of 300 mm4 per hour. As examples of initial evaluation results, resolution of 45-nm L/S patterns and 48-nm4 hole patterns in resist image were obtained. Alignment experiments are on going now, and overlay accuracy around 20-nm (3a) over effective area of 8-in. wafer is being expected.

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The two LEEPL beta-tools were completed in earlier 2002 and have been evaluated for the performance. 5Onm CH patterns and 7Onm L/S patterns are attained and the CD uniformity of 7Onm L/S patterns with 37shots on a 200mm wafer is under 4nm (3) with the LEEPL beta-tools. In addition, it is proved that the fine tuning deflector can correct a mask and a wafer distortion by giving a minute angle to the electron beam. The mask distortion with respect to orthogonality and magnification is decreased on a wafer by 1/5. By means of this fine tuning deflector, Mix & Match accuracy with any other lithography tools will be better and difficulty of lx stencil mask fabrication will be easier. Referring to the data which has been obtained with the evaluation of the LEEPL beta-tools, the first LEEPL production tool dubbed "LEEPL-3000" is under construction to realize the satisfactory ability for 65nm node device fabrication. The shipping of the first LEEPL-3000 is scheduled in earlier 2003 and it is earlier than any other Next Generation Lithography technologies.

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