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.

Low-energy electron beam lithography with 30 nm resolution

Abstract: Electron beam lithography (EBL) with a low accelerating voltage ( approximately 2 kV) was utilized for the fabrication of nanostructures. A resolution of 30 nm was achieved for both sparse and dense lines. The high resolution resulted from the low aberrations of the electron optics system of the field emission scanning electron microscope used as an EBL machine and from the preferred small-angle forward scattering characteristic of the low-energy exposing electrons. By comparison with 50 kV EBL, the authors show a large reduction in the proximity effect and demonstrate a 60 nm spacing between two large exposed areas. Moreover, it is shown that the critical dose at 2 kV is more than an order of magnitude less than that at 50 kV exposures.

Coulomb Interaction Effect in Cell Projection Lithography

Abstract: In cell projection lithography, critical dimension (CD) control is one of the important issues for device fabrication as well as resolution. Because plural patterns are exposed in one shot under the same dose, the proximity effect correction is more difficult than in the conventional variable-shaped beam (VSB) lithography. We have analyzed the CD deviation in order to obtain high CD accuracy of less than 0.02 µ m (range) which is sufficient for manufacturing 1 G dynamic randam access memory (DRAM). We have found that the Coulomb interaction effect plays an important role in CD deviation. We have proposed a new exposure intensity distribution (EID) function which contains a factor introduced for the first time to compensate the proximity effect and the Coulomb interaction effect simultaneously. The results indicate that the new EID function is very effective to compensate the Coulomb interaction effect and improve the CD deviation from 12% (0.03 µ m) to 6% (0.015 µ m) for 0.25 µ m lines-and-spaces (L/S) patterns.

A study of proximity effects at high electron‐beam voltages for x‐ray mask fabrication. I. Additive mask processes

Abstract: Proximity effects can be reduced when exposing x‐ray mask membranes by increasing the electron‐beam accelerating voltage. Forward scattering in the resist is reduced and exposure due to backscattered electrons is also reduced since the more energetic electrons are able to pass through the electroplating base and thin mask membrane. In this article, a detailed study of the proximity effect at high electron‐beam voltages for additive process x‐ray mask fabrication will be discussed. The main contributors to the proximity effect at high beam voltages were found to be backscattering from the x‐ray mask membrane, fast secondary electron production by the incident beam, backscattering from the Au/Cr plating base, and finite beam size. The proximity effect was found to still be significant at 75 kV; but, greatly reduced compared to the measured effect at 50 kV. A Monte Carlo simulation program which included the effects of fast secondary electron production was used to analyze the experimental results. Simulated...

Lithography evaluating method, lithography process and program

Abstract: PROBLEM TO BE SOLVED: To provide a lithography evaluating method capable of accurately evaluating a proximity effect even when a substrate is not composed of a uniform material. SOLUTION: The lithography evaluating method includes the step (step S1) of preparing the substrate comprising a silicon substrate 1 and a wiring structure containing a silicon oxide film 12 on a silicon substrate 11, and Cu wiring layers 13, 14 in the silicon oxide film 12; the step (step S2) of sorting the substrate into a plurality of areas to be evaluated; and the step (step S3) of comparing the number of the wiring layers with the number of critical wiring layers in each area to be evaluated, to evaluate the proximity effect in each area to be evaluated. COPYRIGHT: (C)2005,JPO&NCIPI