Proximity effect (electron beam lithography)

About: Proximity effect (electron beam lithography) is a research topic. Over the lifetime, 940 publications have been published within this topic receiving 8508 citations.

Proximity effect correction in electron-beam lithography

Abstract: Many techniques have been proposed for the reduction or correction of the proximity effect. These include the use of an appropriate beam energy, multilayer resists, dose correction, and correction exposures. Here, special emphasis is placed on dose correction schemes. In particular, the relationship between these and a typical correction exposure scheme (GHOST) is described. The popular "self-consistent" schemes are in widespread use. However, alternative dose correction schemes with attractive attributes exist, although they are not as well known. Two of these are described. One treats electron lithography as a form of incoherent imaging, characterized by a modulation transfer function (MTF). The method consists of transforming the pattern data to account for this MTF, thus eliminating the proximity effect. This scheme is both computationally efficient and accurate. The other scheme is an extension of GHOST in which dose corrections are computed by simulating the effects of a correction exposure: it too is fast and accurate.

Suppression of superconductivity dominated by proximity effect in amorphous MoSi nanobelts

Abstract: A traditional concept proposes that the suppression of the transition temperature ${T}_{c}$ in an amorphous nanobelt is driven by enhanced disorder, which accounts for localized Cooper pairs. However, in this paper, we observe ${T}_{c}$ suppression in an amorphous molybdenum-silicide (MoSi) nanobelt, which scales as the inverse square of the width but contradicts disorder theory. Instead, the transition regime can be well described by Cooper pair diffusion in the proximity effect. Both the nonlinear reduction of the switching current density and the abnormal increase of the effective retrapping current density with the reduction of the width further verify the proximity-induced relation. Therefore, we attribute the main size dependence of the suppressed superconducting properties in the MoSi nanobelt to the proximity effect rather than disorder. We speculate that the competition between superconductivity and disorder only appears at the two narrow edge bands rather than the entire nanobelt. Subsequently, the reduction in width does not produce a significant impact on superconductivity for disorder, and only the proximity effect plays an overwhelming role in the MoSi nanobelt.

The effect of resist contrast on linewidth error induced by e‐beam proximity exposure

Abstract: In electron beam lithography, resolution is limited by two important factors: proximity effect and resist contrast. The relation between these two factors is investigated in a chemically amplified negative resist system. It has been discovered that proximity effect induced critical dimensions variation is not monotonically dependent on resist contrast; the worst proximity effects are apparent at medium contrast values. At higher contrast values, increasing the contrast can reduce the proximity effect; at lower values, increasing the contrast worsens the proximity effect. It has also been found that a parabola‐shaped curve is obtained when interproximity effect is plotted as a function of exposure dose. Dissolution rate ratio and overdevelopment effect were used to explore the impact of resist contrast on e‐beam proximity effect.

Studies on correction accuracy of proximity effect for the pattern area density method in electron beam direct writing

Abstract: This article describes the correction accuracy of the pattern area density method for 0.2 μm rule patterning, carrying out simulation and experiments. To enhance the μm correction accuracy at the boundary zone of the different pattern densities, a novel technique using the gradient vectors of the pattern density is proposed and its capability for sub‐0.15‐μm pattern fabrication is demonstrated.