No abstract

In this article, we demonstrate the concept of scattering masks for ion-beam proximity lithography. In this process, stencil mask openings are fabricated with larger-than-nominal sizes and are coated with a conformal scatter layer that reduces the size of the features at the mask surface. The process reduces the complexity of etching high aspect-ratio mask openings. Printed images of masks with 100 and 40 nm circular openings, fabricated from masks with 225 nm openings, are shown. The printing process has excellent exposure latitude: less than a 20% change in critical dimension is observed for a 33% change in dose for 40 nm structures. We show that the diffuse background exposure that results from ions traversing through the scatter layer is around 0.1% of the primary exposure for a 2 μm pitch pattern.

Three-dimensional finite element method analysis on the tunnel-soil-underground pipeline was carried out based on the ABAQUS program. PSI element was applied to simulate the interaction between the pipelines and soil. Parameters such as an elastic modulus of soil, stress release rate, at-rest lateral pressure coefficients, an elastic modulus of pipelines, and buried depths of tunnels were analyzed. The effects of tunnel excavation on the displacement of existing pipelines were investigated, and the settlement relationships were obtained. The relationship between each parameter and surface settlement was determined by the grey relational analysis method to analyze each parameter’s sensitivity to the settlement of the pipeline, which can provide a reference for emphasis and methods of shield tunneling support. Finally, a formula of the settlement relationship between the maximum surface settlement and pipelines deformation was proposed for different pipe-soil relative stiffness. The formula was applied in the practical case. Compared with the field monitoring results and FEM computer results, it has been found that the proposed normalized formula is consistent with the measured results and numerical simulation of the pipeline settlement.

Fabrication of open stencil masks with asymmetric void ratio for the ion projection lithography space charge experiment J.

High precision stress measurement of ion projection lithography mask membranesFabrication of open stencil masks with asymmetric void ratio for the ion projection lithography space charge experiment J.Experimental results of the stochastic Coulomb interaction in ion projection lithography