No abstract

No abstract

Electron projection lithography (EPL) is a realistic technology for the 65nm node and below, as a complementary technology of optical lithography especially for contacts and gate layers because of its high resolution and large process margin. Nikon has developed an EPL exposure tool as an electron-beam (EB) stepper and the first generation EB stepper; NSR-EB1A is now almost completed as an R&D tool for the 65nm technology node. Using a ϕ200mm reticle, a 20mm×25mm exposure field is realized. Full-field exposure performance of NSR-EB1A is shown. A 70nm isolated line and 1:1 nested lines are simultaneously resolved, as are 50nm 1:2 nested lines. 60nm contact holes are resolved with a depth of focus over a 10μm range and dosage window over ±6%. Stitching accuracy is about 20nm (3σ) and the single machine overlay is about 30nm (mean + 3σ). These data mean sufficient performance for device manufacturing of the 65nm technology node. The concept of a large subfield is one candidate for resolution and throughput enhancement in EPL production tool. The Coulomb blur is directly measured by an aerial image sensor for a large subfield and small beam half-angle, and the data show good agreement with simulations. It is shown that throughput over 20 wafers per hour (ϕ300mm) is realistic and achievable in a production tool of a 45nm technology node.

The third harmonic of a Q-switched Nd:YAG laser is used to decompose iodobenzene C6H5I dissolved in benzene. Photoacoustic (PA) signals are observed simultaneously. They initially have a finite value arising not only from the solvent but also from the reaction of the radicals, C6H5· and I·, since the quantum yield of the photodissociation is reported to be approximately 100%. The PA intensity increases with the number of laser shots since the the reaction product, iodine, forms a charge-transfer complex with the solvent, which also absorbs the laser light. From the ratio of initial PA signal to that due to the complex, the quantum yield of chemically induced PA is deduced to be less than 60%.

Electron Projection Lithography (EPL) is considered one of promising technologies below 45nm node, especially for contact/via holes and gate layers.EPL has some nice features such as very high resolution to be applied for two device nodes, large process margin associated with large depth of focus and an expected lower CoO.Nikon has been developing an EPL tool, so-called EB Stepper.NSR-EB1A is the first EB Stepper that was designed as R&D tool for 65nm technology node and that was already delivered for Selete (Semiconductor Leading Edge Technologies, Inc.) at Tsukuba in Japan.Nikon has developed two NSR-EB1A tools so far, one system for Selete as a 300mm wafer system and the other for Nikon's development and evaluation as a 200mm wafer system.Both tools have already started to show full performance data and good stability characteristics. The latest EB1A tool performance shows very good results in such data as the resolution of 50nm 2:1 L/S and 60nm 1:1 dense contact holes patterns, stitching accuracy of around 18nm, and overlay accuracy of around 20nm(X+3sigma).