A method for in-situ luminous flux monitoring and exposure dose compensation

Abstract

The invention relates to an in-situ luminous flux monitoring and exposure dose compensating method. The method comprises the following steps: measuring the luminous flux of a main light beam going through an exit slit and entering a vacuum chamber before a lithography experiment by using a photodiode, monitoring the intensity of main light beam going through the exit slit and entering the vacuum chamber and the luminous flux of stray lights directly proportional to the main light beam during experimental exposure, and adjusting the exposure time of each lithographic area in real time accordingto the change of the intensity of the stray lights to compensate for the exposure dose in order to keep the exposure dose constant in the XIL large-area exposure pattern splicing process, ensure thatthe nanostructure in the finally obtained large-area exposure pattern is uniform and effectively improve the performances of a device formed by the exposure pattern.

Description

Technical field [0001] The invention relates to an in-situ luminous flux monitoring and exposure dose compensation method. Background technique [0002] X-ray interference lithography (XIL) is a new advanced micro- and nano-processing technology that uses the interference fringes of two or more coherent X-beams to expose photoresist. It can carry out nanostructure processing of tens or even a dozen nanometer cycles . XIL technology is suitable for the preparation of large-area nano-periodic structures with a period of less than 100nm. Compared with other methods such as photolithography, it can obtain high-quality sub-50nm high-density periodic nanostructures more reliably. It is used in nanoelectronics, micro-nano There are a wide range of applications in the fields of optics, nanobiology, nanodevices and materials, and photonic crystals. [0003] For a single exposure, the area of ​​the exposed pattern obtained by the XIL technology is related to the area of ​​the mask grating....

AI Technical Summary

Problems solved by technology

If the exposure dose (exposure dose=luminous flux*exposure time) between each region is different during the exposure process, the nanostructure between each region will be uneven, resulting in the inhomogeneity of the nanostructure in the finally obtained large-area pattern, After this pattern is developed into a device, the performance of the device will be affected

[0006] In the actual exposure process, the luminous flux is often difficult to keep constant for a long time, which is caused by many reasons: First, although Shanghai Light Source is now operating in constant current mode, the electron beam current in the storage ring is not constant change, but after continuous attenuation and re-injection, the change of the beam current of the storage ring will affect the luminous flux; secondly, there are multiple insert devices installed in the storage ring, and the change of the gap between the inserts will affect the electron orbit, causing the electron orbit to drift. In particular, the change of the gap between the upstream and downstream inserts adjacent to the lithography beamline has the greatest impact on the lithography beamline. The drift of the electron orbit will cause the change of the light source point, which will affect the luminous flux; finally, the thermal effect of the optical elements in the beamline The impact produces deformation, which also causes a change in luminous flux

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