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.

Charged particle beam exposure and charged particle beam exposure device

Abstract: PURPOSE: To make it possible to make accurately a correction of a proximity effect even if a plurality of base patterned layers are formed by a method wherein pattern data to be exposed on a substrate surface layer to be formed with a pattern is split into small regions to calculate the density of the existence of the pattern and moreover, the pattern is drawn at a main exposure calculated on the basis of the intensity of the whole scattering of a charged particle beam. CONSTITUTION: A layer 3 to be processed is deposited on a base pattern 2 formed on a substrate 1 into a pattern form. Moreover, a resist layer, which is used as a surface layer, is applied to perform a patterning of the resist layer using a charged particle beam and thereafter, a pattern is transferred to the layer 3 by etching using the patterned resist layer as a mask. That is, in the first of a back scattering, which is generated in the interface between the resist layer and the substrate, of the beam entering one point on the resist layer, the pattern is made to expose to the beam on the layer 3 and the second of the back scattering, the beam entering the lower layer pattern 2 is reentered in the resist layer to make the pattern expose to the beam. Thereby, even if a plurality of base patterned layers, which affect the intensity of the back scattering, are formed, a correction of a proximity effect can be made accurately and at high speed. COPYRIGHT: (C)1995,JPO

Proximity effect correction using a dose compensation curve

Abstract: A new concept, the dose compensation curve, is described for use in a proximity effect correction algorithm. The dose compensation curve links dose compensation factors, developed resist images, and calculated values of energy density at pattern boundaries. An experimentally measured dose compensation curve agrees very well with theoretical predictions. This technique has been successfully implemented in a fast promixity‐effect correction algorithm which automatically corrects the exposure dose factor in the electron‐beam data base for vector scan machines.

Method for electron beam exposure

Abstract: PURPOSE:To reduce the number of shots required for lithography and to prevent a.decrease in a throughput by multiple exposing rectangles having different aspect ratios to be inscribed with an oblique part of an oblique figure, and resolving the oblique part by utilizing bulges of a pattern generated by a proximity effect. CONSTITUTION:When wide figures 2-7 are formed in order to reduce the number of shots while suppressing deterioration of resolution of an oblique part of an oblique figure, exposure amounts are always increased as compared with stepwise parts on superposed parts of the two figures on shaded parts. Then, bulges are generated in the stepwise figures by an influence from the part. This is caused by a proximity effect of an electron beam. If a generally oblique figure is resolved by utilizing a deformation by the proximity effect, the number of shots is decreased. Thus, even when the oblique figure is formed, the number of the shots can be reduced, and a decrease in a throughput can be prevented.

An e‐beam microfabrication system for nanolithography

Abstract: An electron beam lithography system designed for making structures with dimensions in the range 100 to 1000 A is described. The beam diameter is 10 A and the maximum beam energy is 100 keV. The system is calibrated for resist exposure by measuring the beam size and current after magnifying it with projector lenses. The beam is deflected electromagnetically under computer control and vector scanning is used during lithography. The system has been used to make fine lines and grids with linewidths in the range 150 to 500 A. Relatively dense structures with large ratios of resist thickness to linewidth have been demonstrated on both thick and thin electron‐transparent, silicon substrates with the system operated at 50 keV. Results have been obtained on both single layer crosslinked resists and double layers of crosslinked resists and PMMA. It is concluded that finer lines and more densely packed structures over larger areas can be obtained on solid substrates using 100 keV beam energy.

Projection lithography apparatus

Abstract: The invention is directed to a method and apparatus of projection lithography in which the contrast introduced into a radiation sensitive material caused by the proximity effect is effectively removed in a single exposure. Patterned radiation is transmitted through a lens system with at least one lens and a back focal plane filter. The back focal plane filter has at least two apertures, an image aperture and a proximity effect correction aperture. Patterned radiation is transmitted through the image aperture and introduces the desired image into the energy sensitive resist material. A portion of the inverse pattern radiation is transmitted through the proximity effect correction aperture and onto the energy sensitive resist material to effectively remove the contrast therein caused by the proximity effect.