In this work we demonstrate the power, speed and effectiveness of an automated rules-based approach for performing optical proximity correction. The approach applies to both conventional and phase-shifting mask layouts for optical lithography. Complex imaging, substrate and process phenomena can be folded into comparatively few rules parameters. Using simple arithmetic, these parameters pre-compensate the layout for the combined proximity effects. The rules consist of edge rules and corner rules for biasing feature edges and for adding sub-resolution assist features. This paper describes an integrated solution which includes rules parameter generation and fast, hierarchical rules application. Experimental results demonstrate improved edge placements and wider process latitude than for non-corrected layouts.

A new dry developed high resolution positive working system: positive resist image by dry etching PRIME for e-beam and deep UV lithography is proposed. This system is derived from photolithographic diffusion enhanced silylating resist diffusion enhanced silylating resist (DESIRE) process. In this report, we present the advantages of a top imaging scheme for e-beam lithography: forward scattering and proximity effects are considerably minimized. Due to very high contrast (about 6), resolution limits were pushed down to 75 nm lines and spaces in 0.35 μm thick resist; holes of 0.2 μm in 1.2 μm thick resist were obtained. Under deep UV exposure, 0.2 μm lines and spaces in 0.7 μm thick resist were resolved with a mask aligner.

Exposure characteristics of an alternate aperture phase-shifting mask fabricated using a subtractive process will be discussed. The subtractive process, where the phase-shifted regions are etched into a layer below the chromium, is attractive because it allows for the use of conventional chromium-an-quartz blanks, as well as providing more processing flexibility, However, recent results using a subtractive fabrication process have determined that a linewidth variation of -0.05 f..lm exists between features imaged with etched and nonetched regions of the alternate aperture pattern. This article examines some of the potential causes for this linewidth variation, including mask linewidth control, surface roughness, contamination during phase-shift forming etch step, and sidewall profile and position. Results indicate that the sidewall profile and position are critical parameters in defining the wafer feature size. The impact of phase is also investigated. The wafer feature size depends on the depth of the quartz etch and accurate endpointing of the phase-shift depth is essential for maintaining critical dimension uniformity across an features imaged with a phase-shifting mask.

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A new model of polymer silylation is proposed. This model takes into account the reaction of the silylating agent with the hydroxyl groups of the polymer and the relaxation rate of the polymer after reaction. The diffusion coefficient of the silylating agent is supposed to be a function of the expansion of the polymer matrix. At the interface between the silylating agent and the polymer, it is assumed that sorption driven by the pressure of the silylating agent, and desorption driven by the concentration of the silylating agent can occur. The resulting differential equations are solved using a finite element technique and the influence of the main parameters, namely, the reaction rate, the relaxation rate, and the diffusion coefficients is studied.