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To optimize the anti-reflectant material (BARC) in 193nm resist processes requires a careful manipulation of the surface energy of the BARC. In general, the surface energy of the BARC is constant in the unexposed and exposed areas. We have developed a new material with a "switchable" contact angle (SBARC) whose key criteria are as follows: (1) High contact angle at about 70 degrees in the unexposed areas under the resist to prevent developer and water penetration; (2) Maximized adhesive of the SBARC to the resist. (3) Contact angle less than 50 degrees in the exposed areas at the BARC surface to reduce the density of satellite-type defects. The low contact angle in the exposed areas reduces the adhesive forces between the hydrophobic resist residues and the more hydrophilic SBARC surface and thus lowers defects.In addition, the hydrophilic SBARC surface can reduce water drop residues and therefore reduce watermark defects. This paper will also describe our process work to optimize the contact angle of unexposed and exposed BARC surface to reduce pattern collapse and minimize satellite defects. We will also discuss a few methods to improve the surface condition of the SBARC to maximize adhesive forces.Further optimization of the develop process and the refractive index and the absorption coefficient of the SBARC, will provide even better collapse margin for 193-nm resists than the present baseline.

The Multiple E-beam Direct Write (MEBDW) technology has been considered a promising solution for the next generation lithography to delineate 32-nm half-pitch and beyond. A low-energy, say 5 keV, e-beam direct writing system has advantages in lower exposure dosage, less heating effect on resist, and less damage to devices underneath, comparing with a high energy one, such as 50 keV or 100 keV. However, the low-energy electron-beam is easily blurred due to forward scattering in the substrate due to its shallow penetration and hence loses resolution. In this paper, variables affecting patterning fidelity of a raster-scan MEBDW system are investigated.In order to realize a MEBDW system with acceptable throughput, a relatively large beam size is chosen for sufficient beam current to sustain throughput while maintaining enough resolution. The imaging resolution loss and the proximity effect, due to beam blurring through the resist, have been observed. The in-house software MOSES, incorporating the Monte Carlo simulation and the Double Gaussian model was used to evaluate 1-D and 2-D pattern fidelity with various exposure conditions. The line width roughness, which represents 1-D fidelity, was evaluated on 32-nm dense lines. Pattern fidelity of 2-D features such as the zigzag poly line and dense metal patterns was also examined. The impact to LWR of using the edge dithering method, instead of dosage modulation, to control the line width accuracy beyond the pixel size was studied.

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